Question

Each child in a sample of 64

low-income children were administered a language and communication exam. The sentence complexity scores had a mean of 7.63 and a standard deviation of 8.92. Complete parts a through d.

a. From the sample, estimate the true mean sentence complexity score of all low-income children.

(____) (Type an integer or a decimal.)

b. Form a 90% confidence interval for the estimate, part a.

The 90% confidence interval is (_____,____)

.(Round to the nearest hundredth as needed.)

c. Give a practical interpretation of the interval, part b.

A. We are 10% confident that the mean sentence complexity score of all low-income children is outside the confidence interval.

B. We are 90% confident that the mean sentence complexity score of all low-income children is between the endpoints of the confidence interval.

C. We are 90% confident that the mean sentence complexity score of all low-income children is outside the confidence interval.

D. We are 10% confident that the mean sentence complexity score of all low-income children is between the endpoints of the confidence interval.

E. An interpretation cannot be determined.

d.Suppose the true mean sentence complexity score of middle-income children is known to be 15.55. Is there evidence that the true mean for low-income children differs from 15.55?

Yes

No

Answer 1