The information systems department of your firm has developed a new database program to store critical information on point of sale purchases. The purchases are made during a busy time of day when the computer is performing many tasks so the amount of computer time used for each transaction is very critical. The old database program would take an average of 55 milliseconds to retrieve one piece of data. The IS department hopes the new program will reduce this time to retrieve data. The new program was tested during a typical day. The number of data retrievals was 144 and the average time to retrieve a piece of data was 53 milliseconds with a sample standard deviation of 16 milliseconds. a) State the null and alternative hypothesis.
b) Calculate the test statistic.
c) Using the P-value approach in your decision making, at the 0.05 level of significance, is there evidence that the new computer program has reduced the time to retrieve the data? Report p-value and use it to support your conclusion.
d) Does your conclusion in part c) change if an a of 0.025 is used?

Name and describe the three most important measures of central tendency. choose the correct answer below. a. the mean, sample size, and mode are the most important measures of central tendency. the mean of a data set is the sum of the observations divided by the middle value in its ordered list. the sample size of a data set is the number of observations. the mode of a data set is its highest value in its ordered list. b. the sample size, median, and mode are the most important measures of central tendency. the sample size of a data set is the difference between the highest value and lowest value in its ordered list. the median of a data set is its most frequently occurring value. the mode of a data set is sum of the observations divided by the number of observations. c. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is the product of the observations divided by the number of observations. the median of a data set is the lowest value in its ordered list. the mode of a data set is its least frequently occurring value. d. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is its arithmetic average. the median of a data set is the middle value in its ordered list. the mode of a data set is its most frequently occurring value.