Question

A researcher in the field of educational psychology obtains a random sample of 49 fourth grade children and administers a conceptual problem-solving test to them. It is known that fourth graders have an average score of 82 on the test nationally. The children in this study score an average of 86, with a standard deviation of 5. Is the difference significant? What is the critical value (α = 0.05)?

Select one:

a. ±2.021

b. ±2.000

c. ±1.684

d. ±1.671

b. What are the null and alternative hypotheses?

Answer 1

Solution :

Given that ,

n = 49

df = 49 - 1 = 48

Critical value = 2.011

(b)

This is the two tailed test .

The null and alternative hypothesis is

H₀ : = 82

H_a : 82