Problem 20E

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

(a) Find the sample mean and sample standard deviation of these condition numbers.

(b) Construct a dot diagram of the data.

Solution:

Step 1 of 3:

The data regarding the condition numbers of the 30 bridges in New York State is given.

5.08,5.44,6.66,5.07,6.80,5.43,4.83,4.00,4.41,4.38,7.00,5.72,4.53,6.43,3.97,4.19,6.26,6.27,5.36,5.48,4.95,6.33,4.93,5.61,4.66,7.00,5.57,3.40,5.18,5.54.

Using this data we need to find the required values.