It is conjectured that the mean amount of time to type the text message using the Apple iPhone and the mean amount of time to type the text message using a Samsung Galaxy will be the same, and of interest is to test this conjecture versus the alternative that the mean amount of time to type the text message using the Apple iPhone is different from the mean amount of time to type the text message using the Samsung Galaxy. Based on this,state the appropriate null and alternative hypotheses that should be tested.

(b). Consider the information given in part (a). A simple random sample of 12 cell phone users was selected. Each of these 12 cell phone users typed the message using an Apple iPhone and using a Samsung Galaxy, randomized as to which they used first. For each cell phone user the two times were recorded, and then the difference between the Apple iPhone time and Samsung Galaxy time was calculated, producing 12 differences. The mean of this sample of 12 differences was 7.4 seconds, with a standard deviation of 16.2 seconds. It is known that the distribution of all such differences is normally distributed. If appropriate, use this information totest the hypotheses stated in part (a) at the = .01 level of significance