Question

The average daily volume of a computer stock in 2011 was u = 35.1 milion shares, according to a reliable source. A stock analyst believes that the stock volume in 2014 is different from the 2011 level. Based on a random sample of 40 trading days in 2014, he finds the sample mean to be 25,3 million shares with a standard deviation of s 12.1 million shares. Test the hypotheses by constructing a 95% confidence interval. Complete parts (a) through (c) below. (a) State the hypotheses for the test. Ho 7 35.1 million shares H V 35.1 million shares (b) Construct a 95% confidence interval about the sample mean of stocks traded in 2014 The lower bound is milion shares The upper bound is million shares (Round to three decimal places as needed) (c) Will the researcher reject the null hypothesis? OA Reject the null hypothesis because - 35.1 million shares does not fall in the confidence interval OB. Do not reject the null hypothesis because * 35.1 milion shares does not fall in the confidence interval OC. Reject the nul hypothesis because 35.1 million shares talls in the confidence interval OD. Do not reject the null hypothesis because y35.1 million shares falls in the confidence interval

Answer 1

a)

Ho: μ = 35.1 Ha: μ# 35.1

b)

sample mean 'x̄=	25.3
sample size   n=	40
sample std deviation s=	12.1
std error 'sx=s/√n=	1.9132
for 95% CI; and 39 df, value of t=	2.02269092
margin of error E=t*std error    =	3.869767737
lower bound=sample mean-E =	21.43023226
Upper bound=sample mean+E =	29.16976774

c)

A Reject the null hypothesis because y - 35.1 million shares does not fall in the confidence interval

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