The reading speed of second-grade students in a large city is approximately normal, with a mean of
Question:
The reading speed of second-grade students in a large city is approximately normal, with a mean of 92 words per minute (wpm) and a standard deviation of 10 wpm.
(a) What is the probability a randomly selected student from this population will read at more than 97 words per minute?
(b) What is the probability that a random sample of 12 secondgrade students from the city results in a mean reading rate of more than 97 words per minute?
(c) What is the probability that a random sample of 24 secondgrade students from the city results in a mean reading rate of more than 97 words per minute?
(d) What effect does increasing the sample size have on the probability? Provide an explanation for this result.
(e) A teacher instituted a new reading program at school. After 10 weeks in the program, it was found that the mean reading speed of a random sample of 21 second-grade students was 94.6 wpm. What might you conclude based on this result?
(f) There is a 5% chance that the mean reading speed of a random sample of 20 second-grade students will exceed what value?
Step by Step Answer:
Statistics Informed Decisions Using Data
ISBN: 9781292157115
5th Global Edition
Authors: Michael Sullivan