A random sample of 81 female American college students were
A random sample of 81 female American college students were each issued a stopwatch and asked to time themselves as they prepared to attend class on the following Thursday morning. The instructions were to start the watch as soon as their feet touched the floor as they got up and to turn it off as they passed through the door of their residence on the way to class. x = “floor-to-door” time rounded to the nearest minute.
a. What is the population of interest?
b. Draw a histogram of the “floor-to-door” variable using multiples of 10 for class midpoints. Describe the distribution. Does it appear to be approximately normal? Explain.
c. Redraw the histogram using multiples of 5 for class midpoints. Describe the visible patterns displayed by this second histogram that were not visible in the first one. Explain what causes this strange pattern.
d. Would you say the histogram suggests that the variable, amount of time, is approximately normally distributed? What evidence can you find to support your answer?
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