Suppose we are testing the null hypothesis H

for a normal population with

s = 6. A random sample of nine observations is drawn

from the population and we find the sample mean of these observations is

= 17. Calculate

p-value for the test.

II

: 20,H1

: = 20 and the alternative H0

 

 

----------------------------------------------------------------

III

An insurance agent says that the mean cost of insuring a

Honda car

is at least $1350. A random

sample of 9 similar insurance quotes has a mean cost of $1290 and a standard deviation of $70.

Is there enough evidence to r

eject the agent's claim at

= 0.01 .Assume the population is

normally distributed.

-----------------------------------------------------------------

VI

A manufacturer claims that the mean lifetime of its light bulbs is 47 months. 150 bulbs are

s

elected at random, and their mean lifetime is found to be 48 months and their standard deviation

is

found to be 4 months. Can we conclude, at the 0.01 level of significance, that the mean

lifetime of light bulbs made by this manufacturer differs from 47 months?

-----------------------------------------------------------------------------

V

In a test of hypothesis, the null hypothesis is that the population mean is equal to

125 and the

alternative hypothesis is that the population mean is greater than 125. A sample of 100 elements

selected from this population produced a mean of 129.9 and a standard deviation of 17. What is

the approximate p-value for this test

---------------------------------------------------------------------------