Question

An extensive survey in 1970 revealed preschool children spend an average of 6.3 hours per day watching television. The distribution of TV times in normal with a population standard deviation of 2 hours. Last year a sample of 100 preschool children had a mean of 5.8 hours of TV watching per day. Test to determine if the average time preschool children spend watching TV per day has decreased at the 0.01 significance level.

Part A -

Part B -   

Part C - State alpha

Part D - Reject null if     (Answer f should be the inequality symbol, and Answer g should be the value.)

Part E - The test statistic is .

Part F - Write the decision  Either Reject the null or Accept the null

Part G - At  = , there is evidence to

Answer 1

sample mean () = 5.8 hours

population sd() = 2 hours

sample size (n) = 100

a).hypothesis:-

(claim)

b).here, we will do 1 sample Z test for mean.

[ as the population sd is known ]

c).the level of significance () = 0.01

d). reject the null hypothesis if,

[ z critical value for alpha=0.01, left tailed test is = -2.807 ]

e).the test statistic is :-

f).decision:-

reject the null hypothesis.

[

g). at 0.01 , there is sufficient evidence to claim that the average time preschool children spend watching TV per day has decreased.