A market research firm supplies manufacturers with estimates of the retail sales of their products from samples of retail stores. Marketing managers are prone to look at the estimate and ignore sampling error. A random sample of 36 stores this year shows mean sales of 83 units of a small appliance with a standard deviation of 5 units. During the same point in time last year, a random sample of 49 stores had mean sales of 78 units with standard deviation 3 units. Required:Construct a 95 percent confidence interval for the difference in population means.

The 95% confidence interval for the difference in population means is (−26.325175  , 36.325175)

Step-by-step explanation:

Given that :

sample size n₁ = 36

sample mean ₁ = 83

standard deviation ₁ = 5

sample size n₂ = 49

sample mean ₂= 78

standard deviation ₂ = 3

The objective is to construct a 95% confidence interval for the difference in the population means

Let the population means be  and  

The 95% confidence interval or the difference in population means can be calculated by using the formula;

where;

the pooled standard deviation  

= 15.75

degree of freedom =

degree of freedom = 36+49 -2

degree of freedom = 85 - 2

degree of freedom = 83

The Critical t- value 95% CI at df = 83 is

t  critical = T.INV.2T(0.05, 83) = 1.9889

Therefore, for the population mean , we have:

= (83 - 78) ± (1.9889 × 15.75)

= 5 ± 31.325175

= 5  - 31.325175 , 5 + 31.325175

= (−26.325175  , 36.325175)

median is the value separating the higher half of a data sample, a population or probablity distribution from the lower half.

step-by-step explanation:

say you have 3,8,7,3,1,9,8 order them from lowest to highest

if orderd it would be 1,3,3,7,8,8,9 now you take away from the lowest and the highest until you end up in the middle.

so you would remove the 1 and 9 leaving you with 5 digits remaining

when you've reached the middle that would be your answer so in this case the answer is 7

if there were two numbers left say 7 and 5 you'd and them together so 12 then divide by 2 witch would equal 6 so the answer would be 6

good luck on that project hoped i you at all

other answer is correct. i had used the radius of the radius somehow. a website: