Question

1.Suppose you wish to test the null hypothesis that the mean of a population is 100 versus the alternative that the mean is not equal to 100. You then take a sample and calculate a sample of mean of 90. Which of the following conclusions is correct?

a.		You should reject the null hypothesis
b.		You should not reject the null hypothesis
c.		You should reject the null if n > 30, otherwise do not reject
		d.You should accept the alternative hypothesis
		e. You have incomplete information to make a conclusion. You need to know the standard deviation and sample size

Answer 1

Claim: To test whether or not the mean of a population is 100 versus the alternative that the mean is not equal to 100 .

Hypothesis :

Two tailed test

Given that ,

sample mean

We know that the test statistic for this example is

Here , for the calculation of test statitics sample standard deviation ( s) and sample size ( n ) are needed.

These both values are not provided

So, it is not possible to calculate the test statistics and hence hypothesis can not be tested.

Option E ) is correct

e. You have incomplete information to make a conclusion. You need to know the standard deviation and sample size

=====================================================================

Q 2 ) As per the above description

it is not possible to calculate the test statistics and hence hypothesis can not be tested

Option D ) is correct