Question

5)The LIRR carries an average of 125,000 passengers daily with a standard deviation of 4000. The railroad has averaged 126,600 passengers daily for the last 36 snowstorms. At a 5% level of significance does this represent a significant increase in passenger load?

a) find the critical z-score(s) or t-score(s)

b) compute the test statistic

c) state whether or not to reject the null hypothesis

d) answer the question posed at the end of each problem

Answer 1

given data are:-

sample mean () = 126600

sample size(n) = 36

population sd () = 4000

here, as the population sd is known we will do 1 sample Z test for mean.

hypothesis:-

a).the critical z score is :-

[ z critical value for alpha = 0.05,right tailed test = 1.645 ]

b). the test statistic) be:-

c).decision:-

so, we reject the null hypothesis.

d).conclusion :-

there is enough evidence to claim that this represent a significant increase in passenger load at 5% level of significance.

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