Question

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A recent national survey found that high school students watched an average (mean) of 7.2 DVDs per month with a population standard deviation of 1.00. A random sample of 49 college students revealed that the mean number of DVDs watched last month was 6.50. At the .05 significance level, can we conclude that college students watch fewer DVDs a month than high school students?

References

14.

value:
10.00 points

Required information

Exercise 10-7 Part B

(b)	State the decision rule.

Reject H₀ if z > -1.65

Reject H₁ if z < -1.65

Reject H₀ if z < -1.65

Reject H₁ if z > -1.65

References

15.

value:
10.00 points

Required information

Exercise 10-7 Part D

(d)	What is your decision regarding H0 ?

Cannot reject H₀

Reject H₀

Answer 1

Solution :

This is the left tailed test .

The null and alternative hypothesis is ,

H₀ :   = 7.2

H_a : < 7.2

Test statistic = z

= ( - ) / / n

= (6.50 - 7.2) / 1 / 49

= -4.9

= 0.05

Z _0.05 = 1.65

Critical value = 1.65

Reject H₀ if z < -1.65

Test statistic > critical value

Reject H0.