Discussion 2 -Ch.3
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A group of Brigham Young University-Idaho students (Matthew Herring, Nathan Spencer, Mark Walker, and Mark Steiner) collected data on the speed of vehicles traveling through a construction zone on a state highway, where the posted speed was 25 mph. The recorded speed of 14 randomly selected vehicles is given below:
20, 24, 27, 28, 29, 30, 32, 33, 34, 36, 38, 39, 40, 40
a. Find the sample mean and standard deviation for these vehicle speeds (round to 1 decimal place).
b. Find the z-score for a car driving 20 mph in this construction zone (round to 2 decimal places).
c. Find the z-score for a car driving 40 mph in this construction zone (round to 2 decimal places).
d. Determine the quartiles, Q1, Q2 and Q3 (round to 1 decimal place).
e. Compute the interquartile range, IQR.
f. Determine the lower and upper fences. Are there any outliers, according to this criterion?
g. Construct a box plot for the vehicle speeds.