Listed below are speeds mih leagues from southbound traffic

Listed below are speeds (mi/h) leagues from southbound traffic on I-280 near Cupertino, California. This random sample was obtained at 3:30pm on a weekday.Use a .05 level of significance to test the claim of the highway engineer that the standard deviation of speeds is less than 5.0 mi/h
62 61 61 57 61 54 59 58 59 69 60 67
a) statistical hypothesis
b) null hypothesis
c) alternative hypothesis
d) which hypothesis is the claim
e) distribution chosen
f) reason chosen
g) p value
h) circle one; reject Ho or fail to reject Ho
i) concluding sentence

Solution

a) the popullation standard deviation is 5.

b) H0: sigma=5

c) H1: sigma<5

d) the alternative hypothesis.

e) Chi square distribution.

f) Since we are testing for the variance, we square the values and hence use chi square distribuiton.

g) 0.9999

h) fail to reject the null hypothesis.

i) since we fail to reject the null hypothesis, we conclude that the sd is 5.