A local neighborhood has just installed speed bumps to slow traffic. Two weeks after the installation the city recorded the following speeds 500 feet after the last speed bump: 29, 29, 31, 42, 30, 24, 30, 27, 33, 44, 32, 30, 24, 35, 34, 30, 23, 35, 27.

a. Find a 99% one-sided confidence interval on mean speed and assess whether or not the average speed is 25 or less. Assume that the data is normally distributed.

b. Does the normality assumption seem reasonable for these data?

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