Question

1. In a sample of 77 children, the mean age at which the first began to combine words was 16.51 months, with a standard deviation of 9.59 months. Using a level of significance of 0.10, suppose we want to test the claim that the mean age at which children first begin to combine words is different from 14 months.

   1. What is the claim of the problem?

   2. What is the null hypothesis?

   3. What is the alternative hypothesis?

   4. What is the value of the test statistic for this problem?

   5. What is the p-value for this test?

   6. What is the appropriate conclusion based on the claim of the problem?

Answer 1

Solution :

This is two tailed test .

The claim of the problem,

Ha : 14

The null and alternative hypothesis is ,

H0 :   = 14

Ha : 14

Test statistic (t) =

= ( - ) / s / n

= (16.51 - 14) / 9.59 / 77

Test statistic = 2.30

P-value = 0.0244

= 0.10

P-value <

Reject the null hypothesis .

There is sufficient evidence to support the  claim that the mean age at which children first begin to combine words is different from 14 months