Answer:
267 observations are needed.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
Let us assume that the population standard deviation is $12.5.
This means that [tex]\sigma = 12.5[/tex]
Willing to accept only a $1.5 margin of errors in our estimations. How many observations do we need in order to estimate the population mean for the above cost?
This is n for which M = 1.5. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]1.5 = 1.96\frac{12.5}{\sqrt{n}}[/tex]
[tex]1.5\sqrt{n} = 1.96*12.5[/tex]
[tex]\sqrt{n} = \frac{1.96*12.5}{1.5}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*12.5}{1.5})^2[/tex]
[tex]n = 266.8[/tex]
Rounding up:
267 observations are needed.
Maggie bought c CDs for $12 each, b books for $7 each, and a purse costing $24.
a. Write an expression to show the total amount of money Maggie spent.
b. If Maggie bought 4 CDs and 3 books, how much money did she spend?
Answer:
b. (4×12)+(3×7)
48+21= 69
she spent $69
A refrigerator is priced it at $525.50. There is a 6% sales tax rate. What is the sales tax for the refrigerator in dollar and cents?
Answer:
The sales tax for the refrigerator would be $31.53
Hope this helps!
Brainliest??
Answer:
Sales for refrigerator in dollar and cents is $31.53.
Step-by-step explanation
6/100 X $525.50 =
0.6 X $525.50 = $31.53.
Find the side lengths of the triangle in this picture.
Answer:
Hypotenuse: 41 meters, Long leg: 40 meters, Short leg: 9 meters.
Step-by-step explanation:
According to the statement, we have the following information about the lengths of the right triangle:
Hypotenuse
[tex]3\cdot x + 14[/tex]
Long leg
[tex]3\cdot x + 13[/tex]
Short leg
[tex]x[/tex]
By the Pythagoric Theorem, we have the following expression:
[tex](3\cdot x + 14)^{2} = x^{2} + (3\cdot x + 13)^{2}[/tex] (1)
[tex]9\cdot x^{2}+84\cdot x + 196 = x^{2} + 9\cdot x^{2} + 78\cdot x + 169[/tex]
[tex]9\cdot x^{2} + 84\cdot x + 196 = 10\cdot x^{2} + 78\cdot x +169[/tex]
[tex]x^{2} -6\cdot x -27 = 0[/tex]
[tex](x-9)\cdot (x+3) = 0[/tex]
As length is a positive variable by nature, then the only possible solution is [tex]x = 9[/tex]. Lastly, the side lengths of the right triangle are:
Hypotenuse: 41 meters, Long leg: 40 meters, Short leg: 9 meters.
helpppppppppppppp meeeeeeeeeeeeeeeeeeeeeeeeeee
Answer:
Area of a circle= π r square
22/7 × 6 ×6
22/7×36
= 792/7
=113.40
Helllppppp me quick!!!!!!!
Answer:
F(x) =2x+3
Step-by-step explanation:
F(x) =2x+3...............
Answer:
[tex]consider : (0, 3) \: and \: (1, 5) \\ gradient = \frac{5 - 3}{1 - 0} \\ = 2 \\ from : \: y = mx + c \\ consider \: (0, 3) \\ 3 = (2 \times 0) + c \\ c = 3 \\ therefore \: equation \: is : \\ y = 2x + 3[/tex]
Please, help meeeeee
Answer:
y = 500x + 1000
Step-by-step explanation:
The standadrd equation of a line is expressed as y = mx+b
m is the slope
is the y-intercept
Using the coordinate points (0, 1000) and (6, 4000)
Slope = y2-y1/x2-x1
Slope = 4000 - 1000/6-0
Slope m = 3000/6
Slope m = 500
Since the line cut the y axis at y = 1000, hence the intercept b = 1000
Get the required equation;
Reall that y = mx+b
y = 500x + 1000
Which one of the following is an ordered pair?
{-3, 5}
(2, 4, 0)
(0, 6)
1, 3
9514 1404 393
Answer:
(c) (0, 6)
Step-by-step explanation:
Conventionally, an "ordered pair" is a pair of items in parentheses, separated by a comma. The items don't have to be numbers. (0, 6) is an ordered pair.
__
Comments on the other answer choices
Curly braces are usually used as delimiters of a set, not an ordered pair.
Three items do not constitute a "pair." Rather, they are a "triple."
Items without any particular indicator of grouping are usually not considered a "pair."
(x2 + 5x +4) × (x + 4)
׳+9x²+24×+16 ...............
5(9-x)/3 +1 less than 11
find x
Answer:
x > [tex]\frac{1}{5}[/tex]
Step-by-step explanation:
[tex]\frac{5(9-x)}{3+1}<11[/tex]
Add 3 and 1 to get 4.
[tex]\frac{5(9-x)}{4}<11[/tex]
Use the distributive property to multiply 5 by 9−x.
[tex]\frac{45-5x}{4}<11[/tex]
Subtract 45/5 from both sides.
[tex]-\frac{5}{4}x<11-\frac{45}{4}[/tex]
Since 44/4 and 45/4 have the same denominator, subtract them by subtracting their numerators.
[tex]-\frac{5}{4} x<-\frac{1}{4}[/tex]
Multiply both sides by -4/5, the reciprocal of -5/4. Since -5/4 is negative, the inequality direction is changed.
[tex]x>-\frac{1}{4} (-\frac{4}{5} )[/tex]
Multiply -1/4 times -4/5 by multiplying numerator times numerator and denominator times denominator.
[tex]x>\frac{-(-4)}{4 x 5}[/tex]
[tex]x>\frac{1}{5}[/tex]
What is the radius of
this cylinder if the
volume is 75.4 in^3 and
the height is 6 inches
Answer:
Radius of cylinder = 2 inch (Approx.)
Step-by-step explanation:
Given:
Volume of cylinder = 75.4 in³
Height of cylinder = 6 inches
Find;
Radius of cylinder
Computation:
Volume of cylinder = πr²h
Volume of cylinder = (3.14)r²(6)
75.4 = (18.84)r²
(Radius of cylinder )² = 75.4 / 18.84
(Radius of cylinder )² = 4.002123
(Radius of cylinder) = 2
Radius of cylinder = 2 inch (Approx.)
Determine the area of this triangle...
Answer:
650,000 cm²
Step-by-step explanation:
10x6.5=65 METERS squared. They want it in CENTIMETERS squared.
65m² = 650,000cm²
Answer:
32.5[tex]m^{2}[/tex]
Step-by-step explanation:
The coloured triangle with the blank triangle area =
(14m x 6.5m)÷2 = 45.5[tex]m^{2}[/tex]
The blank triangle area =
[(14-10m) x 6.5m]÷2 = 13[tex]m^{2}[/tex]
Therefore:
The coloured triangle area =
(45.5 - 13)[tex]m^{2}[/tex]
=32.5[tex]m^{2}[/tex]
Kiera's dance class starts at 4:30pm and ends at 6:15 pm how long is her dance class
Question 12: Angle M and Angle P are what type of angles?
m
n
o
Р
qr
st
adjacent
right
obtuse
O vertical
Answer:
adjacent anf o vertical
Step-by-step explanation:
help me please thank you
Answer:
m<A = 98.25
m<B = 81.75
m<C = 113
m<D = 113
m<E = 67
Step-by-step explanation:
3x + 12 + 5x - 18 = 180
8x - 6 = 180
8x = 186
x = 23.25
3x + 12
3(23.25) + 12
81.75
5x - 18
5(23.25) - 18
98.25
6y - 5 + 10y - 7 = 180
16y - 12 = 180
16y = 192
y = 12
6y - 5
6(12) - 5
67
10y - 7
10(12) - 7
113
Plz help its my last grade and i really need it to be good
Answer:
Option D
Step-by-step explanation:
[tex]60+45+75=180[/tex]
[tex]Triangle ~has ~the~ sum ~of ~angle =180[/tex]
--------------------------
hope it helps...
have a great day!!
Answer:
D will be your answer!!
Step-by-step explanation:
hope it helps
Find the length of a to the nearest tenth using the Pythagorean theorem
Answer:
Ab^2 = CA^2 + BC^2
8^2 = 6^2 + a^2
64 = 36 + a^2
64-36 = a^2
28 = a^2
square root of 28 = square root of a^2
5 ,29 = a
5 = a
someone please explain they didnt tell me bout this im just a middle schooler
Answer:
r=4.5, d=9
Step-by-step explanation:
So, lets go over two things.
#1 - What is Diamater?
Diamater is the distance from one side of a circle to the other.
#2 - What is radius?
Radius is the distance from any side of the circle, to the middle. This is half of the diamater.
In this case, the distance from one side of the circle to the other is 9in.
So the diamater must be 9.
d=9 in
Since we know the radius is half of the diamater, radius is:
9/2
=
4.5 in
So our radius must be 4.5.
r=4.5
This looks like the top answer.
Hope this helps! :D
Please help me solve this question
The ages of registered voters in Smith County are normally distributed with a population standard deviation of 3 years and an unknown population mean. A random sample of 18 voters is taken and results in a sample mean of 55 years. Find the margin of error for a 95% confidence interval for the population mean. 20.01 20.10 1.282 20.05 1.645 20.025 1.960 20.005 2.576 2.326 You may use a calculator or the common z values above. • Round the final answer to two decimal places.
Answer:
The margin of of error for a 95% confidence interval for the population mean is of 1.39 years.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
The margin of error is:
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Population standard deviation of 3 years
This means that [tex]\sigma = 3[/tex]
Sample of 18 voters
This means that [tex]n = 18[/tex]
Margin of error:
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]M = 1.96\frac{3}{\sqrt{18}}[/tex]
[tex]M = 1.39[/tex]
The margin of of error for a 95% confidence interval for the population mean is of 1.39 years.
Which is an equation for the circle with center (-3 , 1) with a radius of 3?
A. (x−3) 2+(y+1) 2=3
B. (x+3) 2+(y−1) 2=3
C. (x+3) 2+(y−1) 2=9
D. (x−3) 2+(y+1) 2=9
Answer:
The answer is c mate .
Step-by-step explanation:
Have a good time and if you find it useful . please rate brainliest . If not Thanks anyway .
What is the remainder when 26 – 4x4 + 4x2 – 10 is divided by x + 3?
Write only the number for the solution.
the answer is a,I took the test on edu
Milena walked 25.086 kilometers on Monday, 19.8 kilometers on Tuesday, and 7 kilometers on Wednesday. What was the total distance that Milena walked
Which value is a solution of 7/4x^2-2=-0.5+4?
Answer:
x=√154 over 7 , −√154 over 7
Step-by-step explanation:
Answer:
the answer is that x=positive or negative square root of 22 over square root of 7
Step-by-step explanation:
I can’t seem to find the value of n in this peoblem
Answer:
9
Step-by-step explanation:
you can always use guess-and-check:
124 seems rather high
(6)P(2) = 6!/4! = 6x5 ≠ 72
(9)P(2) = 9!/7! = 9x8 = 72
Answer:
i think the value of n is 12
please help, this is urgent!
Quadrilateral WXYZ will be rotated 180° about the origin and then reflected across the y-axis.
W (-7,-2)
X (-4,-2)
Z (-6,-6)
Y (-3,-7)
Choose all of the statements about the quadrilateral and/or the the transformed quadrilateral that are correct.
A. The quadrilaterals will be congruent
B. The Quadrilateral will map onto itself
C. The quadrilateral will now appear in Quadrant 2
D. The quadrilaterals will have the same orientation
E. The quadrilaterals will be similar but not congruent
Answer: the answer is W (-7, -2)
Step-by-step explanation:
Prove the statement below directly from the definitions of the terms.
For all integers n, n2 + n +1 is odd.
Answer:
We know that:
If A is an even integer number, then A + 1 is an odd number
If B is an odd number, then B + 1 is an even number.
We also know that the product of two odd numbers is odd, and the product of two even numbers is even.
We want to prove that:
For all integers n, n^2 + n + 1 is odd.
We have two cases.
If n is even, then:
n^2 is the product of two even numbers, so is even.
n^2 + n is the sum of two even numbers, then it is even.
And:
(n^2 + n) + 1 is an even number plus one, so it is odd.
Now let's assume that n is odd.
n^2 is the product of two odd numbers, then n^2 is odd.
n^2 + n is the sum of two odd numbers, then it is even.
And similar as the previous case:
(n^2 + n) + 1 is an even number plus one, so it is odd.
Scarecrow and the Tin Man are walking in a field toward Emerald City! When they start walking, Scarecrow is 25 meters away and Tin Man is 40 meters away. Scarecrow is walking at a rate of 5 meters per minute and Tin Man is walking at a rate of 10 meters per minute. After how many minutes will Scarecrow and Tin Man be the same distance from Emerald City? What are two equations to solve this problem?
Answer:
3 minutesStep-by-step explanation:
Required equations are:
d = 25 - 5x andd = 40 - 10xSince d is same for both, we substitute d and solve for x:
25 - 5x = 40 - 10x10x - 5x = 40 - 255x = 15x = 3They will be at same distance after 3 minutes
Time be x distance be y
y=25-5xy=40-10xSolve for x
25-5x=40-10x5x=40-255x=15x=3minA store sells small notebooks for $8 and large notebooks for $16. If a student buys 6 notebooks and spends $80, how many of each size did he buy?
Answer:
Small-6
Large-2
Step-by-step explanation:
small-$8
large-$16
$8×6=$48
$80-$48=$32
32÷16=2(large)
ILL MARK BRAINLIEST!
Which of these points lies on the graph of the equation x – 9 = y?
A. (3, 6)
B. (2, 11)
C. (-3,-6)
D. (-2, -11)
Answer:
D. (-2, -11)
Step-by-step explanation:
Since -2 - 9 = -11, it fits into the equation x - 9 = y, with -2 being "x" and -11 being "y".
And out of all the options, D is the only one that works.
The "freshman 15" is the name of a common belief that college students, particularly women, gain an average of 15 pounds during their first year of college. In one study of 110 female first‐year college students (Psychology of Women Quarterly, vol 17, pp.119‐126, 1993), the mean weight was 130.6 pounds at the beginning of the study and 131.4 pounds six months later. The standard deviation was about 20 pounds at each time.
Required:
a. Estimate the change in the mean weight over this six‐month period.
b. Is this sufficient information to find a confidence interval or conduct at estimate about the change in the mean over six months? If not what else do you need to know?
Answer:
A) - 0.8 Ibs
B) There isn't enough information
The standard deviations of the difference scores is needed
Step-by-step explanation:
N = 110 female first year college students
Mean weight at beginning of study = 130.6 Ib
Mean weight after six ( 6 ) months = 131.4 Ib
standard deviation = 20 pounds
A) Determine the change in the mean weight over the six(6) months period
mean weight at beginning - mean weight after six(6) months
= 130.6 - 131.4
= -0.8 Ibs
B) Determine if there is sufficient information to find a confidence interval
There isn't sufficient information to determine the confidence interval but in other to determine the confidence interval or conduct an estimate You need standard deviations of the difference scores to calculate the standard error of mean