For the data in Exercise 6-20,

(a) Construct a stem-and-leaf diagram.

(b) Do any of the bridges appear to have unusually good or poor ratings?

(c) If so, compute the mean with and without these bridges and comment.

Exercise 6-20

The United States has an aging infrastructure as witnessed by several recent disasters, including the I-35 bridge failure in Minnesota. Most states inspect their bridges regularly and report their condition (on a scale from 1€“17) to the public. Here are the condition numbers from a sample of 30 bridges in New York State (https://www.dot.ny.gov/main/bridgedata):

5.08 5.44 6.66 5.07 6.80 5.43 4.83 4.00 4.41 4.38 7.00 5.72 4.53 6.43 3.97 4.19 6.26 6.72 5.26 5.48 4.95 6.33 4.93 5.61 4.66 7.00 5.57 3.42 5.18 4.54