Answer:
a) 15.8 ms-1
b)869 m
Step-by-step explanation:
We have to obtain the resultant velocity by the Pythagorean theory;
R^2= V1^2 + V2^2
Where
R= resultant velocity of the boat
V1= velocity of the boat
V2= velocity of the flowing river
Thus;
R= √V1^2 + V2^2
R= √15^2 + 5^2
R= √225 + 25
R= √250
R= 15.8 ms-1
B) from
v= s/t
Where
v= velocity (resultant velocity in this case)
s= distance
t= time (55 secs)
s= vt
s= 15.8×55
s= 869 m
I need HELP! is the missing value 25?
Answer: choice3) 25
Step-by-step explanation:
The constant ratio of y/x is 2.5
so if the x value is 10 the y value would be 25(10*2.5).
A cognitive psychologist would like to evaluate the claim that the omega-3 fatty acids can help improve memory in normal adult humans. One group of participants is given a large dose of fish extract containing the Omega-3 (500 mg), and a second group is given a placebo containing no Omega-3 (0 mg). The researcher asks each participant to read the front page of a local newspaper thoroughly every morning and to take their prescribed dosage (of either Omega-3 or placebo) immediately afterwards. The researcher gives each participant a memory test at the end of two weeks and records how many news items each participant remembers from the past three weeks of news. Answer the following:
A) What names would you give the independent and dependent variables;
B) Is the dependent variable discrete or continuous?
C) What scale of measurement (nominal, ordinal, interval or ratio; and continuous or discrete) is used to measure the independent variable?
D) What research method is being used (experimental or observational)? Explain why you conclude that the research method is one or the other.
Answer:
(a)
Independent Variable- Dosage of Omega-3 Fatty AcidsDependent Variable - Number of news item remembered(b)Discrete
(c)Ratio Scale and Discrete Variable
(d) Experimental Method
Step-by-step explanation:
The psychologist wants to evaluate the claim that omega-3 fatty acids can help improve memory in normal adult humans.
(a)In the study, the participants in the two groups were given fish extracts containing Omega-3 (500 mg) and no Omega-3 (0 mg).
The memory test involves measuring the number of items each participant remembers from the past three weeks of news.
Therefore:
Independent Variable- Dosage of Omega-3Dependent Variable - Number of news item remembered(b) The dependent variable is discrete since the number of news items remembered can only be whole numbers.
(c)The independent variable is in milligrams of Omega-3 where the placebo is 0 mg. This is a ratio scale since it has an absolute zero.
Since the dosage is given in multiples of 50mg, it is a discrete variable.
(d)Since the psychologist seeks to manipulate the conditions of the study by introducing Omega-3 to some of the participants and placebo to other participants, it is an experimental distribution.
After 2 hours, there are 1,400 mL of fluids remaining in a patient’s IV. The fluids drip at a rate of 300 mL per hour. Let x be the time passed, in hours, and y be the amount of fluid left in the IV, in mL. Write a linear function that models this scenario.
Answer:
[tex] y(2) = 1400[/tex]
Using this condition we got:
[tex]1400= -300*2 +b[/tex]
And solving for b we got:
[tex] b= 1400+ 600= 2000[/tex]
So then our linear function is given by:
[tex] y = -300x +2000[/tex]
Where y is the amount of fluid left and x the number of hours ellapsing
Step-by-step explanation:
We want to set up a linear function like this one:
[tex]y = mx+b[/tex]
Where y is the amount of fluid left, m the slope and b the initial amount. From the info given we know thatm = -300. And we also have the following condition:
[tex] y(2) = 1400[/tex]
Using this condition we got:
[tex]1400= -300*2 +b[/tex]
And solving for b we got:
[tex] b= 1400+ 600= 2000[/tex]
So then our linear function is given by:
[tex] y = -300x +2000[/tex]
Where y is the amount of fluid left and x the number of hours ellapsing
V. Money Magazine reported that the average price of gasoline in the United States during the first quarter of 2008 was $3.46. Assume that the price reported by Money is the population mean, and the standard deviation σ is $0.15. a. What is the probability that the mean price for a sample of 30 gas stations is within $0.03 of the population mean?
Answer:
[tex] z=\frac{3.43 -3.46}{\frac{0.15}{\sqrt{30}}} = -1.095[/tex]
[tex] z=\frac{3.49 -3.46}{\frac{0.15}{\sqrt{30}}} = 1.095[/tex]
And we can find this probability using the normal standard table and we got:
[tex] P(-1.095<z<1.095) = P(z<1.095) -P(z<-1.095) =0.863 -0.137= 0.726[/tex]
Step-by-step explanation:
Let X the random variable that represent the price of a population, and for this case we know the distribution for X is given by:
[tex]X \sim N(3.46,0.15)[/tex]
Where [tex]\mu=3.46[/tex] and [tex]\sigma=0.15[/tex]
And for this case we want to find the following probability:
[tex] P(3.43 \leq \bar X \leq 3.49)[/tex]
And we can use the z score formula given by:
[tex] z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
If we find the z score for the limits we got:
[tex] z=\frac{3.43 -3.46}{\frac{0.15}{\sqrt{30}}} = -1.095[/tex]
[tex] z=\frac{3.49 -3.46}{\frac{0.15}{\sqrt{30}}} = 1.095[/tex]
And we can find this probability using the normal standard table and we got:
[tex] P(-1.095<z<1.095) = P(z<1.095) -P(z<-1.095) =0.863 -0.137= 0.726[/tex]
Explain why the terms of the polynomial y2 + 7 are said to be realitvley prime
Answer:
The terms of the polynomial are relatively prime because the highest integer that divides them both is 1.
Step-by-step explanation:
Two numbers are said to be relatively prime if their greatest common factor ( GCF ) is 1 .
Now, the expression we are given in the question is a polynomial;
y² + 7.
The terms of the polynomial y² + 7 are y² and 7 and have no common factor and in fact cannot be factorized further. Thus, these terms are said to be relatively prime because the highest integer that divides them both is 1.
how to simplify 4e + 6f + 7e - f
Answer:
11e+5f
Step-by-step explanation:
Combine like terms:
4e+7e+6f-f
11e+5f
Answer:
11e +5f
Step-by-step explanation:
4e + 6f + 7e - f
Combine like terms
4e+7e +6f-f
11e +5f
(3х^2y^3)^3 =
3x^5y^6
9х^6y^9
27x^5y^6
27x^6y^9
Answer:
27x^6y^9
Step-by-step explanation:
The outside exponent multiplies all of the inside exponents. The applicable rules of exponents are ...
(ab)^c = (a^c)(b^c)
(a^b)^c = a^(bc)
__
(3x^2y^3) = (3^3)(x^(2·3))(y^(3·3)) = 27x^6y^9
Ronaldo is standing by the edge of a circular lake at point A (shown below). He has to get directly to the other side at point B. Instead of walking around the lake from A to B, he decides that he would rather swim. How far must he swim from A to B if the circumference of the lake is 4.71 miles
The height of a stream of water from the nozzle of a fire hose is modeled by h(x) =-0.03x2+ 2x + 38 where h(x) is the height in feet, of the stream of water x feet from the fire truck. 1. What is the maximum height the water from this nozzle can reach? What is the maximum distance from the firetruck a firefighter can stand and still reach the fire?
Answer:
height: 71.33 feetreach: 82.10 feetStep-by-step explanation:
The equation can be rewritten to vertex form:
h(x) = -0.03(x² - 200/3x) +38
h(x) = -0.03(x² -200/3x +(100/3)²) +38 +.03(100/3)²
h(x) = -0.03(x -33 1/3)² +71 1/3
The vertex is (33 1/3, 71 1/3), so the maximum height the water will reach is 71 1/3 feet.
__
When h(x) = 0, the water reaches as far as it possibly can.
0 = -0.03(x -33 1/3)² +71 1/3
(-71 1/3)/(-0.03) = (x -33 1/3)² . . . subtract 71 1/3; divide by -0.03
√(2377.78) = x -33.33 . . . . . . . . positive square root
82.10 ≈ x
The maximum distance the water will reach is 82.10 feet.
True or False - the following scenario depicts an independent relationship between variables (tree growth and air quality): 20% of trees growing in a particular region are not growing to their expected height. In a particular neighborhood in that region, the Air Quality Index is labeled as "Unhealthy for Sensitive Groups" or worse 30% of the time. 10% of the trees in the region grow in this neighborhood. If you randomly measured the growth of a tree in that neighborhood, then the probability that that tree is not growing to its expected height is 33.33%.
Complete the following subtraction exercises.
10 – 2 =
14 – 6 =
15 – 9 =
17 – 8 =
13 – 5 =
11 – 8 =
20 – 8 =
16 – 7 =
12 – 9 =
21 – 9 =
11 – 6 =
5 – 5 =
4 – 0 =
16 – 8 =
10 – 5 =
18 – 7 =
13 – 8 =
12 – 4 =
Answer:
Below
Step-by-step explanation:
8,8,6,9,8,3,12,9,3,12,5,0,4,8,5,11,5,8. Answers are in order from the first to the last
Please answer this question !! 20 points and brainliest !!
Answer:
yes, they are parallel; the general form equation differs only in the constant.
Step-by-step explanation:
Subtract y from the first equation and multiply by 2.
y -y = 1/2x -y +3
0 = x -2y +6
x -2y +6 = 0 . . . . . put in general form
Compared to the second equation, we see the only difference is in the constant, +6 vs. -8.
This means the lines are parallel.
In an aquarium, there are 4 large fish and 16 small fish. Half of the small fish are blue. One fish is selected at random. Find the probability that it is a small, blue fish. Write your answer as a fraction in simplest form.
Answer:
2/5
Step-by-step explanation:
There are 20 fish, 8 of which are small and blue. Therefore, the probability of randomly selecting a small blue fish is 8/20 = 2/5.
6z+10=-2
pls answer'
i willmarke brainlest
Answer:
Step-by-step explanation: 6z=-2-10
6z= -12
z=-12/6
then z= -2
The container of a breakfast cereal usually lists the number of calories and the amounts of protein, carbohydrate, and fat contained in one serving of the cereal. The amounts for two common cereals are given below. Suppose a mixture of these two cereals is to be prepared that contains exactly 295 calories, 9 g of protein, 48 g of carbohydrate, and 8 g of fat.
a. Set up a vector equation for this problem. Include a statement of what the variables in your equation represent.
b. Write an equivalent matrix equation, and then determine if the desired mixture of the two cereals can be prepared.
$$\begin{matrix}
\text{Nutrient} & \text{General Mills Cherrios} & \text{Quaker 100% Natura Cereal}\
\text{Calories} & \text{110} & \text{130}\
\text{Protein (g)} & \text{4} & \text{3}\
\text{Carbhydrate (g)} & \text{20} & \text{18}\
\text{Fat (g)} & \text{2} & \text{5}\
\end{matrix}$$
Answer:
(a)
[tex]\left[\begin{array}{ccc}110\\4\\20\\2\end{array}\right] x+\left[\begin{array}{ccc}130\\3\\18\\5\end{array}\right] y=\left[\begin{array}{ccc}295\\9\\48\\8\end{array}\right][/tex]
(b)
[tex]\left[\begin{array}{ccc}110&130&295\\4&3&9\\20&18&48\\2&5&8\end{array}\right][/tex]
1.5 servings of cheerios and 1 serving of Quaker 100% natural cereal will give the desired mixture.
Step-by-step explanation:
Given the mixture of cereals below:
[tex]\left|\begin{array}{c|c|c}&$General Mills &$Quaker \\$Nutrient&$Cherrios &100\% $Natural Cereal\\----&---&---\\$Calories&110&130\\$Protein (g)&4&3\\$Carbhydrate (g)&20&18\\$Fat (g)&2&5\end{array}\right|[/tex]
Suppose a mixture of these two portions of cereals is to be prepared that contain exactly 295 calories, 9 g of protein, 48 g of carbohydrate, and 8 g of fat.
(a)Let x be the number of servings of Cheerios
Let y be the number of servings of Natural Cereal
From the table above, we have
[tex]110x+130y=295\\4x+3y=9\\20x+18y=48\\2x+5y=8[/tex]
Then a vector equation for this problem is:
[tex]\left[\begin{array}{ccc}110\\4\\20\\2\end{array}\right] x+\left[\begin{array}{ccc}130\\3\\18\\5\end{array}\right] y=\left[\begin{array}{ccc}295\\9\\48\\8\end{array}\right][/tex]
(b) Next, we obtain an equivalent matrix equation of the data
[tex]\left[\begin{array}{ccc}110&130\\4&3\\20&18\\2&5\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}295\\9\\48\\8\end{array}\right][/tex]
This is of the form AX=B. To solve for X we, therefore have an equivalence matrix:
[tex]\left[\begin{array}{ccc}110&130&295\\4&3&9\\20&18&48\\2&5&8\end{array}\right][/tex]
Next, we row reduce the matrix using a calculator to obtain the matrix:
[tex]\left[\begin{array}{ccc}1&0&1.5\\0&1&1\\0&0&0\\0&0&0\end{array}\right][/tex]
Therefore:
1x+0=1.5
0x+y=1
x=1.5 and y=1
To get the required mixture, we use 1.5 servings of cheerios and 1 serving of Quaker 100% natural cereal.
Diya spent 2/5 of her money on a dress and 1/2 of the reminder on a doll. She spent $8 more o the dress than the doll. How much money did she have left?
year 6 Mathematics
Answer:
$24
Step-by-step explanation:
2/5 — dress
3/5 — remainder
1/2 of remainder = 1/2 × 3/5 = 3/10 — doll
rewrite fraction spent on dress: 4/10
dress - doll = $8
4/10 - 3/10 = 1/10
1/10 = $8
fraction of money left = 10/10 - 4/10 - 3/10
= 3/10
amount of money left = $8 × 3
$24
-3
n is an integer.
Write down the possible values of n.
I
Answer:
since n is an integer you substitute n with all the integers. But since that is too much you should use infinity.
n=[-∞,+∞] where -∞ is a negative infinity which stands for negative numbers and +∞ is a positive infinity where it stands for positive numbers.
an integer contains negative and positive numbers so above is the answer.
Step-by-step explanation:
The product of 5 and the sum of 12 and a certain number is 10. What is the number 4
Answer:
-10
Step-by-step explanation:
5(12 + x) = 10
60 + 5x = 10
5x = -50
x = -10
Which of the functions below could have created this graph?
Answer:
i don't know if this is right or not i did to much work to put it all down but i pretty sure it's C.
how do you find the zero(s) of a polynomial function
Answer:
by using the quadratic formula
Step-by-step explanation:
negative b plus or minus the square root of b squared minus 4ac, then all divided by 2a
Need help ASAP please
Answer:
r = l / π/180× θ
11.6 cm
Step-by-step explanation:
l = π/180 × r × θ
r = l / π/180× θ
r = 12.5 / π/180× 62
r = 11.55156845
I will give brainlisest!!!
Lines x and y are parallel.
Parallel lines x and y are intersected by lines s and t. At the intersection of lines x, t, and s, clockwise from top left, the angles are blank, blank, (6 x + 8) degrees, blank, (7x minus 2) degrees, blank. At the intersection of lines x and y, the angles are 106 degrees, 1, blank, blank. At the intersection of lines y and t, the angles are 2, blank, blank, blank.
Given the diagram, which statement is not true?
m∠1 = (6x + 8)° because they are corresponding angles.
m∠1 = 74° because ∠1 is supplementary to the angle marked 106°.
m∠1 + (6x + 8)° + (7x – 2)° = 180° because they can form a straight line which measures 180°.
(7x – 2)° + m∠2 = 106° because the sum of the remote interior angles equals the exterior angle.
Answer:
the third one since the other ones are correct
Step-by-step explanation:
Answer:
3
Step-by-step explanation:
If 7 - y = 6, then y=
Answer:
y=1
Step-by-step explanation:
7-y=6
6+1=7
7-1=6
Hope this helps:)
Stay Safe
Answer:
y =1
Step-by-step explanation:
7 - y = 6
Subtract 7 from each side
7 - y-7 = 6 -7
-y = -1
Multiply each side by -1
-y*-1 = -1 *-1
y = 1
The graph shows the estimated value of a piece of land, where x is the number of years since the purchase and y is the estimated value in thousands of dollars. The graph shows the estimated value of a piece of land, where x is the number of years since the purchase and y is the estimated value in thousands of dollars. What was the purchase price of the land? $10,200 $100,000 $102,000 $1,000,000
The correct answer is B. $100,000
Explanation:
The graphic shows how the value of the piece of land changed from the moment it was bought to five years later by relating the value in the y-axis to the years passed in the x-axis. The initial value or purchase price of the land is the value shown in the y-axis at 0 years (x-axis )or the first orange dot because this is the initial value of the land before any time had passed. According to this, the value is $100,000 considering the number in this intersection is 100 but this is the value in thousands of dollars.
Answer:
It's B or $100,000
Step-by-step explanation:
What is a perfect cube and how can you check if a given number is a perfect cube? Explain why.
Answer:
Read below.
Step-by-step explanation:
A perfect cube is a number cubed (If that makes sense). Such as 3³ will equal a perfect cube because it's being multiplied by itself 3 times. 3×3×3=9. It will work for any whole number. You can check if a given number is a perfect cube by using the cube root ([tex]\sqrt[3]{x}[/tex]).
Hope it makes sense!
Step-by-step explanation:
A perfect cube is a cube whose cube root can be easily gotten by using methods such as factor method eg 125 is a perfect cube whose cube root is 5. You can know if a number is a perfect cube 1.) if it gives you a perfect cube root
To examine the effect of high-dose green tea extract on weight loss, researchers conducted a randomized, double-blind trial on a random sample of 115 women with obesity from Taiwan. Some of these women were randomly assigned to the main treatment group taking a high-dose green tea extract ("EGCG") daily for 12 weeks. The published abstract of this 2015 study reports that, "Significant weight loss, from 76.8 ± 11.3 kg to 75.7 ± 11.5 kg (p = 0.025), was observed in the treatment group after 12 weeks of high-dose EGCG treatment."
Which of the following inference procedures would be used to reach the quoted conclusion?
a. Z procedure for a proportion
b. Chi-square for two-way tables
c. Chi-square for goodness of fit
d. Two sample t procedure for two means
e. One sample or matched-pairs t procedure for a mean
f. ANOVA for several means
Answer:
d. Two sample t procedure for two means.
Step-by-step explanation:
The study have a treatment group, which is the group of women that are taking the high dose of green tea extract, and a control group, in order to compare. They are assigned randomly to each group.
Then, the difference fo the two sample means is calculated and a t-test is performed in order to conclude if the two populations means are significantly different.
Apparently they are significantly different, as this is the conclusion with a P-value of 0.025.
A game is played using one die. If the die is rolled and shows 1, the player wins $5. If the die shows any number other than 1, the player wins nothing. If there is a $1 charge to play the game, what is the game’s expected value?
Answer:
1/5
Step-by-step explanation:
i had a similar question
For each roll you start with paying 2 dollars and you only with 10 dollars one out of 6 rolls (on average).
So the cost for one play is 2 dollars and your win is 10/6.
Value is -2+10/6=-1/3 dollars
So you lose 1/3 dollars on average with each game
since you have no limited rolls u put 1/5
this from another question but both same just different numbers
Robin read somewhere that adding salt to water while heating it will raise the temperature of
the water causing it to boil faster. To test this claim, she filled 30 identical pots with one quart
of water. She randomly selected 15 of the pots and added 1 teaspoon of salt. She then placed
each pot on identical burners set to the highest setting. She measured the water temperature
In each pot after 5 minutes.
Is Robin's research method an example of an observational study experiment, or
simulation?
b
If Robin does find that there is a difference between the water temperatures in the pots
with salt compared to those without can she conclude that the salt caused the
difference in temperature?
Answer:
a. An experiment
b. No
Step-by-step explanation:
a. Robin's research method can be concluded to be an experiment because she has a testable group (pots of water with salt) and a control group (pots of water without salt).
2. Based on this alone, she cannot conclude that the salt caused the
difference in temperature because she has not set some appropriate conditions which are to be met for this test.
Suppose that it costs $200 per day to search for chanterelle mushrooms at Pt. Reyes National Seashore. On an average day, the total weight of mushrooms M found at Pt. Reyes is M = 100x-x^2 pounds ,where x is the number of people mushroom hunting on that day. Chanterelles can be sold for $60 per pound. How many more people will go mushroom hunting than is socially optimal?
Answer:
For an overall profit, we need at least 97 people to go mushroom hunting.
Any number of people that is more than the socially optimal number should go mushroom hunting on any given day.
Step-by-step explanation:
The socially optimal number of people that will go mushroom hunting is the number where amount spent to go mushroom hunting equally balances the amount obtained by selling the mushrooms obtained.
If x people go mushroom hunting in a day, the total cost of hunting for that day = 200x
The amount of mushroom obtained is given as
M = (100x - x²) in pounds
The selling price of 1 pound = $60
The cost of M pounds = 60M = 60(100x - x²)
= (6000x - 60x²)
At socially optimal number,
200x = 6000x - 60x²
60x² - 6000x + 200x = 0
60x² - 5800x = 0
x(60x - 5800)
x = 0 or (60x - 5800) = 0
x = 0 or x = (5800/60) = 96.67
Socially optimal number of people = 0 or 96.67
For realistic purposes, we take the socially optimal number of people that went mushroom hunting as 96.67
Any number above this number will result in an overall profit, and any number below it results in an overall loss.
So, for an overall profit, we need at least 97 people to go mushroom hunting.
Hope this Helps!!
Answer:
48 people
Step-by-step explanation:
When allocating resources to a particular task it is important to assign optimal units of resources.
In this scenario if the people hunting mushrooms are too many they will not make profit. But an optimal number will guarantee everyone makes positive profit.
Optimal = (M÷x)Px - 200= 0
Optimal= {(100x -x^2) ÷ x} * 60 = 200
Optimal = 6000 - 60x = 200
x= 96.666~ 97 people
However to maximise profit MTB = MTC
Socially Optimal quantity = 60(100x - x^2) -200
∂(Socially Optimal amount) ÷ ∂ x= 6000 - 120x - 200
x = 48.33~ 48 people
So 48 more people go mushroom hunting than is socially optimal
Find the equation for the plane through the points Upper P0 (-2 ,2 ,-5),Q0 (1,2,-1), and Upper R0 (-1,-5,4 ).
The equation of plane is:________
Answer:
28x - 23y - 21z = 3
Step-by-step explanation:
First, we need to find two vectors in the plane as:
vector PQ = Q - P = (1, 2, -1) - (-2, 2, -5) = (3, 0, 4)
vector PR = R - P = (-1, -5, 4) - (-2 ,2 ,-5) = (1, -7, 9)
Then, we need to find a normal vector to the plane as:
PQ x RQ = ((0*9)-(4*-7), -(3*(9)-(4*1), (3*-7)-(0*1))
PQ x RQ = (28, -23, -21)
Finally, the equation of a plane is:
A(x-x0) + B(y-y0) + C(z-z0) = 0
Where (A,B,C) is a normal vector to the plane and (x0, y0, z0) is a point in the plane. So, replacing (A,B,C) by (28, -23, -21) and (x0, y0, z0) by P0(-2,2,-5), we can write the equation of the plane as:
28(x+2) - 23(y-2) - 21(z+5) = 0
Solving, we get:
28x + 56 - 23y + 46 - 21z - 105 = 0
28x - 23y - 21z - 3 = 0
28x - 23y - 21z = 3