PART 1

A major automobile manufacturers has produced compact cars We are interested in determining whether or not the MPG (miles per gallon) of the  automobiles is significantly lower than 28. A random sample of eight cars from the manufacturer is selected for testing the MPG. Use 90% level of confidence.

State the null and alternative hypothesis. You can use the symbols tab to copy the symbols you need.

H0:

HA:

Test whether or not the average MPG (miles per gallon) of the  automobiles is significantly lower than 28. Show all the steps and your conclusion.

PART 2

Quality control department of a certain cellphone network provider estimates that  2%  of all cell phone connections by that provider are dropped. They select a random sample of  1,500  calls and find that 40 calls are dropped mid conversation.

State the null and alternative hypothesis for testing whether the proportion of calls that are dropped is different from 2%. You can use the symbols tab to copy the symbols you need.

H0:

HA:

Verify that the sample is sufficiently large to use the normal distribution.

Complete the hypothesis test at 1% level of significance and state complete conclusions: