keith tabulated the values for the average speeds on each day of his road trip as 61.5, 62.2, 55.7, 50.6, 71.3, 70.8, and 66.8 mph. he wishes to construct a 90% confidence interval. what value of t* should keith use to construct the confidence interval? answer choices are rounded to the thousandths place. 1.415 1.943 1.440 1.895