Answer:
n = 10
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] [ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = 12 and d = 5 and [tex]S_{n}[/tex] = 345, thus
[tex]\frac{n}{2}[/tex] [ (2 × 12) + 5(n - 1) ] = 345 ( multiply both sides by 2 )
n( 24 + 5n - 5) = 690 ← distribute and simplify left side
n(19 + 5n) = 690
19n + 5n² = 690 ( subtract 690 from both sides )
5n² + 19n - 690 = 0 ← in standard form
(5n + 69)(n - 10) = 0 ← in factored form
Equate each factor to zero and solve for n
5n + 69 = 0 ⇒ 5n = - 69 ⇒ n = - [tex]\frac{69}{5}[/tex]
n - 10 = 0 ⇒ n = 10
However, n > 0 , thus n = 10
How many solutions does the following system have x+y=3, 2x+2y-5
Answer:
Step-by-step explanation:
x + y = 3
2x + 2y = 5
-2x - 2y = -6
2x + 2y = 5
0 not equal to -1
no solution
Determine the decision criterion for rejecting the null hypothesis in the given hypothesis test; i.e., describe the values of the test statistic that would result in rejection of the null hypothesis. Suppose you wish to test the claim that , the mean value of the differences d for a population of paired data, is greater than 0. Given a sample of n15 and a significance level of 0.01, what criterion would be used for rejecting the null hypothesis?
Answer:
reject null hypothesis if calculated t value > 2.624
Step-by-step explanation:
n = 15
To calculate degree of freedom, n -1 = 14
The claim says ud>0
The decision rule would be to reject this null hypothesis if the test statistics turns out to be greater than the critical value.
With df =14
Confidence level = 0.01
Critical value = 2.624 (for a one tailed test)
If the t value calculated is > 2.624, we reject null hypothesis.
Using the t-distribution and it's critical values, the decision rule is:
t < 2.624: Do not reject the null hypothesis.t > 2.624: Reject the null hypothesis.At the null hypothesis, we test if the mean is not greater than 0, that is:
[tex]H_0: \mu \leq 0[/tex]
At the alternative hypothesis, we test if the mean is greater than 0, that is:
[tex]H_1: \mu > 0[/tex].
We then have to find the critical value for a right-tailed test(test if the mean is more than a value), with 15 - 1 = 14 df and a significance level of 0.01. Using a t-distribution calculator, it is [tex]t^{\ast} = 2.624[/tex].
Hence, the decision rule is, according to the test statistic t:
t < 2.624: Do not reject the null hypothesis.t > 2.624: Reject the null hypothesis.A similar problem is given at https://brainly.com/question/13949450
football team, won 35 out of 39 games over a period of 4 years. if they keep winning pace, predict how many games you would expect them to win over the next 78 football games
Answer:
70
Step-by-step explanation:
If the team continues with same pace, they expected wins as per previous ratio:
35/39*78 = 70Expected wins 70 out of 78 games
HELP PLEASE!! (math)
Answer:
Hey there!
We can write: -2+9=7.
Let me know if this helps :)
Answer:
[tex]\large \boxed{{-2+9=7}}[/tex]
Step-by-step explanation:
-2 is also 0-2
The arrow goes from 0 to -2.
-2 + 9 = 7
The arrow goes from -2 to 7.
while jeff was replacing the obstruction of light on a cell tower, he accidentally dropped his cell phone. If he was 150 ft up at the time, approximately how long did it take the phone to reach the ground
Answer:
3.19 seconds
Step-by-step explanation:
Given:
Phone gets dropped from a Height = 150 ft
To find:
Time taken for the phone to reach the ground = ?
Solution:
First of all, let us learn about the formula of distance in terms of Initial speed u; Time t and Acceleration a:
[tex]s=ut+\dfrac{1}{2}at^2[/tex]
Here the phone is dropped from a height so a = g m/[tex]s^2[/tex] i.e. acceleration due to gravity.
g = 9.8 m/[tex]s^2[/tex]
s = 150 ft
Initial velocity, u = 0
Putting all the values in the formula:
[tex]150=0 t+\dfrac{1}{2}gt^2\\\Rightarrow 50=\dfrac{1}{2}\times 9.8 \times t^2\\\Rightarrow t^2=\dfrac{50}{4.9 }\\\Rightarrow t^2=10.20\\\Rightarrow t = 3.19\ sec[/tex]
So, the time taken is 3.19 seconds.
In 2004, 50 out of every 100 drivers at the National Trucking Company passed their driver's license exam on their first try. In 2005, 62 of the drivers passed on their first attempt. What was the percent increase in the passing rate?
Answer:
I believe it's a 12 percent increase.
Step-by-step explanation:
50/100= 50%
62/100= 62%
62%-50%=12%
If carpet costs $24.61 per square yard and is available in whole square yards only, find the cost of carpeting the three bedroom floors in the accompanying floor plan.
Answer:
Step-by-step explanation:
The area of each bedroom is the product of its length and width.
Bdrm 1 area = (14 ft)×(14 ft) = 196 ft²
Bdrm 2 area = (11 ft)×(12 ft) = 132 ft²
Bdrm 3 area = (12 ft)×(11 ft) = 132 ft²
Then the total area of carpet needed is ...
196 ft² +132 ft² +132 ft² = 460 ft²
There are 9 ft² in each square yard, so the number of square yards needed is ...
(460 ft²)/(9 ft²/yd²) = 51.11... yd²
Since we can only obtain whole square yards, 52 square yards are needed. The cost of that will be ...
(52 yd²)×($24.61/yd²) = $1279.72
The cost of carpeting for the three bedrooms will be $1279.72.
For real numbers x and y, what is the largest possible value of [tex]5 - (x-3)^2[/tex]?
Answer:
5
Step-by-step explanation:
Anything other than making x - 3 = 0 will make x - 3 have a value. No matter what happens (x - 3)^2 is positive. There is a minus sign outside the brackets which makes (x - 3)^2 negative.
That means that something is always taken away from 5 unless x = 3. Try and find any value that will make a number bigger than or equal to five that isn't x = 3.
By the way, I'm assuming the question is y = 5 - (x - 3)^2
Use the definition of continuity and the properties of limits to show that the function f(x)=x sqrtx/(x-6)^2 is continuous at x = 36.
Answer:
The function is continuous at x = 36
Step-by-step explanation:
From the question we are told that
The function is [tex]f(x) = x * \sqrt{ \frac{x}{ (x-6) ^2 } }[/tex]
The point at which continuity is tested is x = 1
Now from the definition of continuity ,
At function is continuous at k if only
[tex]\lim_{x \to k}f(x) = f(k)[/tex]
So
[tex]\lim_{x \to 36}f(x) = \lim_{n \to 36}[x * \sqrt{ \frac{x}{ (x-6) ^2 } }][/tex]
[tex]= 36 * \sqrt{ \frac{36}{ (36-6) ^2 } }[/tex]
[tex]= 7.2[/tex]
Now
[tex]f(36) = 36 * \sqrt{ \frac{36}{ (36-6) ^2 } }[/tex]
[tex]f(36) = 7.2[/tex]
So the given function is continuous at x = 36
because
[tex]\lim_{x \to 36}f(x) = f(36)[/tex]
9sin(Θ)-7=0. Solve the trigonometric equation
Step-by-step explanation:
here's the answer to your question
If vectors i+j+2k, i+pj+5k and 5i+3j+4k are linearly dependent, the value of p is what?
Answer:
[tex]p = 2[/tex] if given vectors must be linearly independent.
Step-by-step explanation:
A linear combination is linearly dependent if and only if there is at least one coefficient equal to zero. If [tex]\vec u = (1,1,2)[/tex], [tex]\vec v = (1,p,5)[/tex] and [tex]\vec w = (5,3,4)[/tex], the linear combination is:
[tex]\alpha_{1}\cdot (1,1,2)+\alpha_{2}\cdot (1,p,5)+\alpha_{3}\cdot (5,3,4) =(0,0,0)[/tex]
In other words, the following system of equations must be satisfied:
[tex]\alpha_{1}+\alpha_{2}+5\cdot \alpha_{3}=0[/tex] (Eq. 1)
[tex]\alpha_{1}+p\cdot \alpha_{2}+3\cdot \alpha_{3}=0[/tex] (Eq. 2)
[tex]2\cdot \alpha_{1}+5\cdot \alpha_{2}+4\cdot \alpha_{3}=0[/tex] (Eq. 3)
By Eq. 1:
[tex]\alpha_{1} = -\alpha_{2}-5\cdot \alpha_{3}[/tex]
Eq. 1 in Eqs. 2-3:
[tex]-\alpha_{2}-5\cdot \alpha_{3}+p\cdot \alpha_{2}+3\cdot \alpha_{3}=0[/tex]
[tex]-2\cdot \alpha_{2}-10\cdot \alpha_{3}+5\cdot \alpha_{2}+4\cdot \alpha_{3}=0[/tex]
[tex](p-1)\cdot \alpha_{2}-2\cdot \alpha_{3}=0[/tex] (Eq. 2b)
[tex]3\cdot \alpha_{2}-6\cdot \alpha_{3} = 0[/tex] (Eq. 3b)
By Eq. 3b:
[tex]\alpha_{3} = \frac{1}{2}\cdot \alpha_{2}[/tex]
Eq. 3b in Eq. 2b:
[tex](p-2)\cdot \alpha_{2} = 0[/tex]
If [tex]p = 2[/tex] if given vectors must be linearly independent.
Emily and Kate were at a cheerleading competition this fall.They cheered 12 rounds. Each round lasted 8.24 minutes. Calculate the total number of minutes, Emily cheered and the total number of minutes Kate cheered at the competition
Answer:
98.88
Step-by-step explanation:
Given: They cheered 12 rounds. Each round = 8.24
To find the total number, multiply how much one round is with the total number of rounds.
8.24
× 12
-----------
1648
+ 8240
----------
98.88
Each girl cheered 98.88 minutes. If you need this estimated, the answer would be 99 minutes.
In a survey of 15000 students of different schools, 40% of them were found to have tuition before the see examination. Among them 50% studied only mathematics ,30% only science and 10% studied others subject. how many student studied mathematics as well as science.
Answer:
600
Step-by-step explanation:
first, 40% of 15000 is 6000,
10% of 6000, which is the number of students studying mathematics as well as science, 600
Answer:
•600 students studied both the subject.
3 x {(300 - 70 ÷ 5) - [3 x 23 - (8 - 2 x 3)]}
A.657
B.2433
C. -843
Answer:
657
Step-by-step explanation:
pemdas
The value of the expression 3 x {(300 - 70 ÷ 5) - [3 x 23 - (8 - 2 x 3)]} is 657.
Hence option A is correct.
Given is an expression, 3 x {(300 - 70 ÷ 5) - [3 x 23 - (8 - 2 x 3)]}, we need to simplify it,
Let's break down the expression step by step:
First, let's simplify the expression inside the innermost parentheses:
8 - 2 x 3 = 8 - 6 = 2
Next, let's simplify the expression inside the brackets:
3 x 23 - 2 = 69 - 2 = 67
Now, let's substitute the simplified expression inside the brackets back into the original expression:
(300 - 70 ÷ 5) - 67
Next, let's simplify the expression inside the remaining parentheses:
70 ÷ 5 = 14
Now, let's substitute the simplified expression inside the parentheses back into the expression:
(300 - 14) - 67
Next, let's simplify the expression inside the remaining parentheses:
300 - 14 = 286
Now, let's substitute the simplified expression inside the parentheses back into the expression:
286 - 67
Finally, let's perform the subtraction:
286 - 67 = 219
Now, let's multiply the result by 3:
3 x 219 = 657
Therefore, the value of the expression 3 x {(300 - 70 ÷ 5) - [3 x 23 - (8 - 2 x 3)]} is 657.
Learn more about expression click;
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A cupboard costing Rs.16800 is depreciated at the rate of 15% per year. What will be the cost of the cupboard after 2 years.
Answer:
Rs. 11132
Step-by-step explanation:
formula for depriciation= P(1-R/100)^T
p= principal, r=rate, t=time
Answer:
15162
Step-by-step explanation:
after 1 year= 16800*95%= 15960
after 2 year= 15960*95%= 15162
If a person earns $8.74 per hour, estimate how much the person would earn per year. Assume a person works 40 hours per week and 50 weeks per year.
Answer:
$17,480 per year.
Step-by-step explanation:
Amount earned per hour = $8.74
If a person works for 40 hours every week for 50 weeks in a year, number of hours worked in a year = [tex] 40hrs*50weeks = 2000 hrs [/tex]
Estimated amount earned per year by the person = [tex] 2000hrs * 8.74 dollars [/tex]
= $17,480 per year.
please help me in these question ????
A school bag contains 12 pens of which 5 are red and the other are black. 4 pens are selected from the bag.
(a) How many different samples of size 4 pens are possible?
(b) How many samples have 3 red pens and 1 black pen?
(c) How many samples of size 4 contain at least two red pens?
(d) How many samples of size 4 contain
If the average yield of cucumber acre is 800 kg, with a variance 1600 kg, and that the amount of the cucumber follows the normal distribution.
1- What percentage of a cucumber give the crop amount between and 834 kg?
2- What the probability of cucumber give the crop exceed 900 kg ?
Answer:
Step-by-step explanation:
A school bag contains 12 pens of which 5 are red and the other are black. 4 pens are selected from the bag.
(a) How many different samples of size 4 pens are possible?
12C4=12!/(4!*8!)=495
(b) How many samples have 3 red pens and 1 black pen?
5C3*7C1
5C3=5!/(3!*2!)=10
7C1=7!/(1!*6!)=7
=>5C3*7C1=10*7=70
(c) How many samples of size 4 contain at least two red pens?
(5C2*7C2)+(5C3*7C1)+(5C4*7C0)
5C2=5!/(2!*3!)=10
7C2=7!/(2!*5!)=21
5C3=5!/(3!*2!)=10
7C1=7!/(1!*6!)=7
5C4=5!/(4!*1!)=5
7C0=7!/(0!*7!)=1
=>(5C2*7C2)+(5C3*7C1)+(5C4*7C0)=285
(d) How many samples of size 4 contain at most one black pen?
(7C1*5C3)+(7C0*5C4)
7C1=7!/(1!*6!)=7
7C0=7!/(0!*7!)=1
5C3=5!/(3!*2!)=10
5C4=5!/(4!*1!)=5
=>(7C1*5C3)+(7C0*5C4)=(7*10)+(1*5)=75
Identify each x-value at which the slope of the tangent line to the function f(x) = 0.2x^2 + 5x − 12 belongs to the interval (-1, 1).
Answer:
Step-by-step explanation:
Hello, the slope of the tangent is the value of the derivative.
f'(x) = 2*0.2x + 5 = 0.4x + 5
So we are looking for
[tex]-1\leq f'(x) \leq 1 \\ \\<=> -1\leq 0.4x+5 \leq 1 \\ \\<=> -1-5=-6\leq 0.4x \leq 1-5=-4 \\ \\<=> \dfrac{-6}{0.4}\leq 0.4x \leq \dfrac{-4}{0.4} \\\\<=> \boxed{-15 \leq x\leq -10}[/tex]
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
Using derivatives, it is found that the x-values in which the slope belong to the interval (-1,1) are in the following interval is (-15,-10).
What is the slope of the tangent line to a function f(x) at point x = x_0?It is given by the derivative at x = x_0, that is:
m = f'(x_0)
In this problem, the function is:
f(x) = 0.2x^2 + 5x − 12
Hence the derivative is:
f'(x) = 0.4x + 5
For a slope of -1, we have that,
0.4x + 5 = -1
0.4x = -6
x = -15.
For a slope of 1, we have that,
0.4x + 5 = 1.
0.4x = -4
x = -10
Hence it is found that the x-values in which the slope belong to the interval (-1,1) are in the following interval is (-15,-10).
More can be learned about derivatives and tangent lines at;
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Find the area of the figure.
A =
Is it m, m2, or m3
Answer:
348 m^2
Step-by-step explanation:
The figure is made up of a rectangle 24 m by 12 m, and a triangle with a 24 m base and a 5 m height.
A = LW + bh/2
A = 24 m * 12 m + (24 m)(5 m)/2
A = 288 m^2 + 60 m^2
A = 348 m^2
Which statements are true about triangle QRS?
Select
three options.
Answer:
The side opposite <Q is RS
The hypothenuse is QR
The side adjacent to <Q is QS
Step-by-step explanation:
Side RS is directly opposite <Q. The first statement provided in the options is correct.
The side that is opposite to <R is QS. The second statement in the options is not correct.
The longer leg of a right triangle is always the hypotenuse. Side QR in ∆QRS is the hypotenuse. The third statement given in the options is correct.
The side adjacent to <R is not SQ. RS is the side adjacent to <R. The fourth statement in the given options is not correct.
Side QS is adjacent to <Q. The fifth option is correct.
Answer:
A, C, E
Step-by-step explanation:
on edge! hope this helps!!~ (‐^▽^‐)
use a paragraph, flow chart, or two column proof to prove the angle congruency
Answer: see proof below
Step-by-step explanation:
Statement Reason
1. ∠CAX ≅ ∠ BAX 1. Given
2. AC ≅ AB 2. Given
3. AY ≅ AY 3. Reflexive Property
4. ΔCAY ≅ ΔBAY 4. SAS Congruency Theorem
5. CY ≅ BY 5. CPCTC
6. ∠CYA ≅ ∠BYA 6. CPCTC
7. ∠CXY ≅ ∠ BXY 7. Given
8. ΔCYX ≅ ΔBYX 4. AAS Congruency Theorem
9. ∠XCY ≅ ∠XBY 9. CPCTC
Step-by-step explanation:
Hope it helps u
plz mark it as brainlist
xThe closing price of Schnur Sporting Goods Inc. common stock is uniformly distributed between $18 and $28 per share. What is the probability that the stock price will be: More than $20? (Round your answer to 4 decimal places.)
Answer:
The probability is [tex]P(X > 20 ) = 0.8[/tex]
Step-by-step explanation:
From the question we are told that
The closing price of Schnur Sporting Goods Inc. common stock is uniformly distributed between $18 and $28 per share.
Given that the stock is uniformly distributed then the probability that the stock price will be more than $20 is mathematically evaluated as
[tex]P(X > 20 ) = 1 - P(X < 20 )[/tex]
Since it is uniformly distribute between $18 and $28 per share then we can solve is as follows
=> [tex]P(X > 20 ) = 1 - [\frac{ 20 - 18 }{28 -18} ][/tex]
=> [tex]P(X > 20 ) = 0.8[/tex]
what number has 7 ten thousands, 1 thousand, 1 hundred, and no ones?
Answer:
[tex]71,100[/tex]
Step-by-step explanation:
If you are trying to find a number that is written in word form, we can just use place values to find what goes where.
A number is broken down into this:
Ten thousands, thousands, hundreds, tens, ones.
If they have 7 ten thousands, the first digit will be a 7.
If they have 1 thousand, the second digit will be a 1.
If they have 1 hundred, the third digit will be a 1.
Since nothing is stated about tens, we assume it's value is 0.
And since there are no ones, it's value is 0.
So:
71,100.
Hope this helped!
Find the least whole number that can replace
to make the statement true.
110< =47
Answer:
it is false
Step-by-step explanation:i cant explain but trust
If we were to make a poset of the form (A, |), where is the symbol for divisibility, which of the following sets A would yield a poset that is a total ordering?
I. A- (1, 4, 16, 64)
II. A- (1.2,3, 4, 6, 12)
III. A 1,2,3, 4, 6, 12, 18, 24)
IV. A+{1 , 2, 3, 6, 12)
Answer:
IV. A+{1, 2, 3, 6, 12}
Step-by-step explanation:
The set of natural numbers form a poset number under relation of > or =. The discrete variables are used to form a poset. The symbols for divisibility in poset form are when an integer is divided by the variable without integer. The correct answer is therefore 4th option.
The intersection of plane A and plane S will be
The intersection of lines n and k is
Point X is the intersection of
Answer:
bjbjbfbdvdjbfv
Step-by-step explanation:
fdbfdvbdjv
A sample of a radioactive substance decayed 11% over the course of 3 weeks. How many grams were in the sample originally if 30.26 grams of the substance were remaining after the 3 weeks?
Answer:
34 grams
Step-by-step explanation:
If the remaining sample has 30.26 grams of radioactive substance, and 11% of it decayed, that means that 30.26 grams is 89% of the original. Let the original be x.
30.26=0.89x
Multiply both by one hundred
3026=89x
Divide both by 89
34=x
x=original, so the original was 34 grams.
In a random sample of people, the mean driving distance to work was miles and the standard deviation was miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a % confidence interval for the population mean . Interpret the results. Identify the margin of error.
Complete Question
In a random sample of ten people, the mean driving distance to work was 23.1 miles and the standard deviation was 6.6 miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 99% confidence interval for the population mean Interpret the results. Identify the margin of error.
Answer:
The 99% confidence interval is [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
The margin of error is [tex]E = 6.783[/tex]
Step-by-step explanation:
From the question we are told that
The sample mean is [tex]\= x = 23.1[/tex]
The standard deviation is [tex]\sigma = 6.6 \ miles[/tex]
The sample size is n = 10
Generally the degree of freedom is mathematically represented as
[tex]df = n-1[/tex]
=> [tex]df = 10-1[/tex]
=> [tex]df =9[/tex]
Given that the confidence level is 99% , the n the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha =1\%[/tex]
[tex]\alpha =0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] with a df of 9 from from the student t-distribution table the value is
[tex]t _{\frac{\alpha }{2} , df } = 3.250[/tex]
Generally the margin of error is mathematically represented as
[tex]E = t_{\frac{\alpha }{2} , df } * \frac{\sigma }{\sqrt{n} }[/tex]
[tex]E = 3.250 * \frac{6.6 }{\sqrt{10} }[/tex]
[tex]E = 6.783[/tex]
The 99% confidence interval is
[tex]\= x - E < \mu < \= x + E[/tex]
=> [tex]23.1 - 6.78 < \mu <23.1 + 6.78[/tex]
=> [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
Subtract 2x^2 -9x - 7 from 8x^2 -5x + 9.
Answer:
-6x² -4x -16
Step-by-step explanation:
be watchful of signs to avoid making errors
Find the sum. 31.25 + 9.38
Answer:
40.63
Step-by-step explanation:
31.25+9.38= 40.63
Hope this helps
Answer: 40.63
Look at the image for shown work.