Find the length x of QR

Complete Question

In a sample of 80 light bulbs, the mean lifetime was 1217 hours with a standard deviation of 52 hours. a. Find the 95% confidence interval for the mean lifetime of this type of bulb. Justify the reason you chose the distribution used to construct the confidence interval. b. How many light bulbs must be sampled so that a 95% confidence interval will specify the mean lifetime to within [tex]\pm 8 \ hours[/tex]?

Answer:

a

    [tex]1206 <  \mu <  1228 [/tex]

The reason why a normal distribution was chosen is because the sample size is large enough that is  [tex]n > 30[/tex]  

b

   [tex]n =162 [/tex]

Step-by-step explanation:

From the question we are told that

    The sample size is  n  =  80  

    The sample mean is  [tex]\= x = 1217[/tex]

     The standard deviation is  [tex]\sigma = 52[/tex]

From the question we are told the confidence level is  95% , hence the level of significance is    

      [tex]\alpha = (100 - 95 ) \%[/tex]

=>   [tex]\alpha = 0.05[/tex]

Generally from the normal distribution table the critical value  of   is  

   [tex]Z_{\frac{\alpha }{2} } =  1.96[/tex]

Generally the margin of error is mathematically represented as  

      [tex]E = Z_{\frac{\alpha }{2} } *  \frac{\sigma }{\sqrt{n} }[/tex]

=>    [tex]E = 1.96  *  \frac{ 52}{\sqrt{80} }[/tex]

=>    [tex]E = 11.395 [/tex]

Generally 95% confidence interval is mathematically represented as  

      [tex]\= x -E <  \mu <  \=x  +E[/tex]

=>   [tex]1217  -11.395 <  \mu <  1217  + 11.395[/tex]

=>   [tex]1206 <  \mu <  1228 [/tex]

Generally the sample size is mathematically represented as  

   [tex]n = [\frac{Z_{\frac{\alpha }{2} } *  \sigma }{E} ] ^2[/tex]

Here  E =  8

=>   [tex]n = [\frac{1.96  * 52 }{8} ] ^2[/tex]

=>   [tex]n =162 [/tex]

Answer:

can you not just divide by 2 because you want to serve half the people?

Step-by-step explanation:

Answer:

128

Step-by-step explanation:

If you multiply you get it.

Answer:

The GCF of these numbers are 32.

Step-by-step explanation:

All of these integers are able to be divided, and by the first number.

Hope this helps! :3

Answer:

You have to find the most simple estimation by finding the nearest whole number, but the actual answer in 2 5/12

Answer:

10.1 cups left

Hope this helps!

Can you pls give brainly if this helps

Answer:

5 dollars and 75 cents.

Step-by-step explanation:

I think you mean 4 shirts are 23$? If so ,you would divide 23 by 4 to get how many dollars is 1 shirt. 23/4 = 5.75

Answer:

Adaptive evolution is always changing because the environment is changing continuously.

Hence,

The right answer would be :

Adaptive evolution is a fluctuating change in a trait

Step-by-step explanation:

Answer:

o.29 answer of this question

Answer:

0.29

Step-by-step explanation:

0 . 8 9

-0 . 6 0

-------------

0 . 2 9

--------------

Hope this helps

plz mark as brainliest!!!!!!!!

Answer:

8

Step-by-step explanation:

you can multiply 4 by another number to get 8

but you can’t multiply 6 by any whole number to get 8

Answer:

The answer is 8

Step-by-step explanation:

You can multiply 4 by two and get 8, but you can't multiply 6 by any whole number and get 8.

4 times 6= 24

6 times 4=24

4 times 3=12

6 times 2=12

4 times 15=60

6 times 10=60

Answer:

The discount is 2.1 dollars

Answer: $ 200

Step-by-step explanation:250 * 0.20 = $50 sale

250 - 50 = $200

Answer:

10x^4

Step-by-step explanation:

The solution to the given expression is 10x⁴ which represents its sum.

Algebraic expressions are mathematical statements with a minimum of two terms containing variables or numbers. Unknown variables, numbers, and arithmetic operators make up an algebraic expression.

The expression is given in the question, as follows:

2x⁴ + 8x⁴

We have to determine the sum or difference of the given expression.

As per the question, we have

2x⁴ + 8x⁴

Combine the likewise terms in the above expression, and we get

10x⁴

Thus, the solution to the given expression is 10x⁴.

Learn more about the algebraic expression here :

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Answer:

C. 65°, 115°

Step-by-step explanation:

3x - 5 + 2x - 15 = 180

5x - 20 = 180

5x = 180 + 20

5x = 200

x = 200/5

x = 40

5x - 20 = 3*40-5 = 120 - 5 = 115

2x - 15 = 2*40 - 15 = 80 - 15 = 65

Answer:

x=16 because the proportional size, this also means that if the -84 becomes 16 in proportion size.

Answer: -1 [(y-b)/m]+x=a

Step-by-step explanation:

(Y-b) / m = x-a

[(y-b)/m] -x =-a

-1 [(y-b)/m]+x=a

Answer:

54

Step-by-step explanation:

92 (how much his sister has) - 38 (how much he has) = 54 (how much more money his sister has then him)

Answer: His sister had 54 more dollars than him.

Step-by-step explanation: 92 (sister's amount) -38 (Bobby's amount) = 54 (total difference).

Answer:

x= - 1

y= 1

Step-by-step explanation:

qwertyuiopsknzvzbjzjjs

Answer:

5cm

Step-by-step explanation:

a^2+b^2=c^2

9+16=x^2

25=x^2

x=5

Hope this helps!

Answer:

E) By the Mean Value Theorem, there is a time when the speed of the plane must equal the average speed of 176 mi/hr. The speed was 100 mi/hr when the plane was accelerating to 176 mi/hr and decelerating from 176 mi/hr.

Step-by-step explanation:

In this question we have the average velocity v = 2200/12.5

= 176miles/hr

The function Which describes the velocity of a plane is continuous. At point t, f(t) is equal to 176. So by the mean value theorem we arrive at a conclusion that the velocity is going to attain the speed of 100 miles per hour twice. The first time is during acceleration, and the second time is during deceleration. So by this, the answer to this question is option E.

Answer:

$492.80

Step-by-step explanation:

The discount= 12%*$560/100%

= $67.20

The discounted= Selling price- discount

= $560 - $67.20

= $492.80

Answer:

6.61=6.610

Step-by-step explanation:

6.61=6.610

After point we can increase no. Of zero.

Answer:

B. 0.75x + 1.25y [tex]\leq[/tex] 15

Answer:

The answer would be c

Step-by-step explanation:

If you look at the vertices you will see that none of them have any of the same vertices.

Answer:

The 90% confidence interval is  [tex]0.199 <  p < 0.261 [/tex]

The sample size to develop a 95% confidence interval is [tex]n = 2032 [/tex]  

Step-by-step explanation:

From the question we are told that

   The sample size is n =500

    The sample proportion is  [tex]\^ p = 0.23[/tex]

From the question we are told the confidence level is  90% , hence the level of significance is    

      [tex]\alpha = (100 - 90 ) \%[/tex]

=>   [tex]\alpha = 0.10[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex]Z_{\frac{\alpha }{2} } =  1.645[/tex]

Generally the margin of error is mathematically represented as  

     [tex]E =  Z_{\frac{\alpha }{2} } * \sqrt{\frac{\^ p (1- \^ p)}{n} } [/tex]

=>   [tex]E =  1.645 * \sqrt{\frac{0.23 (1- 0.23)}{500} } [/tex]

=>   [tex]E =  0.03096 [/tex]

Generally 90% confidence interval is mathematically represented as  

      [tex]\^ p -E <  p <  \^ p +E[/tex]

=>    [tex]0.23  -0.03096  <  p < 0.23  +  0.03096 [/tex]

=>   [tex]0.199 <  p < 0.261 [/tex]

From the question we are told the confidence level is  95% , hence the level of significance is    

      [tex]\alpha = (100 - 95 ) \%[/tex]

=>   [tex]\alpha = 0.05[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex]Z_{\frac{\alpha }{2} } =  1.96[/tex]

The margin of error is given as [tex]E = 0.01[/tex]

Generally the sample size is mathematically represented as  

    [tex]n = [\frac{Z_{\frac{\alpha }{2} }}{E} ]^2 * \^ p (1 - \^ p ) [/tex]

=>    [tex]n = [\frac{1.96 }{0.01} ]^2 *0.23 (1 - 0.23 ) [/tex]      

=>    [tex]n = 2032 [/tex]  

The above answer is correct! The correct response is A.

Just got it right on edge 2020, hope this helps!! Good luck, and have a great day! :)

The solution is, Using a half-angle identity we get the exact value of

sin 3pi/8 is ±√[(2 + √2) / 4].

Here, we have,

The half angle formula of sin in trigonometry is

sin A/2 = ±√[(1 - cos A) / 2].

If 0 < x < π/2 , then cos x > 0.

now, we have,

sin 3pi/8

here, A/2 = 3pi/8  so, A = 3pi/4 = 6π/8

applying this  half angle formula of sin in trigonometry

we get,

sin 3π/8 = ±√[(1 - cos 6π/8) / 2]

              = ±√[(1 + 1/√2) / 2]

              = ±√[(2 + √2) / 4]

so, we get,

sin 3π/8 = ±√[(2 + √2) / 4]

Hence, The solution is, Using a half-angle identity we get the exact value of sin 3pi/8 is ±√[(2 + √2) / 4].

For more such question on sin in trigonometry visit:

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The lengths of line segments AB and BC are AB = 10; BC = 28

Parallelograms are shapes with parallel and equal opposite sides

The given parameters are:

AB = 3y - 2

BC = x + 12

DC = y + 6

AD = 2x - 4

The above means that:

AB = DC

BC = AD

So, we have:

AB = DC

3y -2 = y + 6

Collect like terms

3y - y = 2 + 6

2y = 8

Divide by 2

y = 4

Also, we have:

BC = AD

x + 12 = 2x - 4

Collect like terms

2x - x = 4 + 12

x = 16

The lengths AB and BC are given as:

AB = 3y - 2

BC = x + 12

So, we have:

AB = 3*4 - 2

AB = 10

BC = x + 12

BC =16 + 12

BC = 28

Hence, the lengths of line segments AB and BC are AB = 10; BC = 28

Read more about parallelograms at:

https://brainly.com/question/24056495

Answer:

D

Step-by-step explanation:

Answer:

21

Step-by-step explanation:

Answer:

10

Step-by-step explanation:

I just guessed and check :)

But if you recheck my answer it's correct!

Angela: 10 years

Cat: 10 months

In 1 year:

Angela: 11 years

Cat: 22 months

I hope this helps!

Answer:

I think Angela is 10 years old today.

Answer:

B,C,F

Step-by-step explanation: