The average daily volume of a computer stock in 2011 was ų=35.1 million 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 30 trading days in 2014, he finds the sample mean to be 32.7 million shares, with a standard deviation of s=14.6 million shares. Test the hypothesis by constructing a 95% confidence interval. Complete a and b A. State the hypothesis B. Construct a 95% confidence interval about the sample mean of stocks traded in 2014.

a

   The  null hypothesis is  

    The  alternative hypothesis  

b

 The   95% confidence interval is  

Step-by-step explanation:

From the question the we are told that

      The  population mean is  

      The  sample size is  n = 30

       The  sample mean is  

       The standard deviation is  

Given that the confidence level is   then the level of significance is mathematically represented as

=>              

Next we obtain the critical value of from the normal distribution table

    The value is  

Generally the margin of error is mathematically represented as

substituting values

The 95% confidence interval confidence interval is mathematically represented as

substituting values