Question

A random sample of n 1-14 winter days in Denver gave a sample mean pollution index x1 43. Previous studies show that σ1 . 23. For Englewood (a suburb of Denver , a random sample of n2 . 16 winter days gave a sample mean pollution index of x2 = 36 Previous studies show that σ2 13. Assume the pollution index is normally distributed in both Englewood and Denver (a) Do these data indicate that the mean population pollution index of Englewood is different (either way) from that of Denver in the winter? Use a 1% level of significance. (1) What is the level of significance? State the null and alternate hypotheses. () What sampling distribution will you use? What assumptions are you making? O The Student's t. We assume that both population distributions are approximately normal with known standard deviations. The standard normal., We assume that both population distributions are approximately normal with known standard deviations The standard normal. We assume that both population distributions are approximately normal with unknown standard deviations The Student's t We ssune thet both population dstrbutions are approximatey nomal with unknon stancdard devaions

Answer 1

	Denver	Englewood
Mean	43	36
Standard Deviation	23	13
Number of sample	14	16

Given is the above i formation

Assume Denver "1 "and Englewood " 2"

first we frame hypothesis

a)

1)The level of significance 0.01 is related to the 99% confidence level.

2) Answer is Ho : µ 1 = µ 2 H 1 : µ 1 ≠ µ 2

B) the standard normal we assume that the both the population distribution is approx normal with known standard deviations.

the value of t statistics is

111) P value