Previous studies on sleep tendencies report that, on average, an adult american will sleep for 6 hours each night with a standard deviation of 0.75 hours. you survey a srs of 100 adult americans and determine that the mean sleep time is 5 hours. which hypothesis test should be used here?
a. one-sample t-test for means.
b. one-sample z-test for means.
c. one sample z-test for proportions.
d. one sample t-test for proportions.
e. chi-squared goodness of fit test.

b) One sample z-test for means

Step-by-step explanation:

Normal Distribution

we have μ₀ (population mean from previous studies)

sample size    n  =  100

standar deviation of population   σ  = 0.75

And it was determined from sample, that μ = 5 : so we want to know if, at some significance level that value (which is smaller than population mean ) could help in relation to decide about rejecting hypothesis  H₀

We should use a z one tail-test for means (left tail)

step-by-step explanation:

c) the median for town a 30" is greater than the median for town b 25"

step-by-step explanation:

town a, median = q2 = 30

town b, median - q2 = 25

so the median for town a 30" is greater than the median for town b 25"