In a Gallup Lifestyle Poll concerning American tipping attitudes, the Gallup News service (on January 8, 2007) reported results that allow construction of two contingency tables given below. The first table uses row percentages to investigate a possible relationship between recommended tip percentage and income level, and the second table uses column percentages to investigate a possible relationship between whether or not a customer has ever left a restaurant without tipping because of bad service and the customer€™s recommended tip percentage.

a. Using the first table, construct a percentage bar chart of recommended tip percentage for each of the three income ranges. Interpret the results.
b. Using the second table, construct a percentage bar chart of the categories €œ Yes, have left with-out tipping€ and €œ No, have not left without tipping€ for each of the three appropriate tip percentage centage categories. Interpret the results.

Transcribed Image Text:

Appropriate Tip Percent Income Less than $30,000 $30,000 through S74999| $75,000 or more | Less than 15% | 28,41% 15.31% 8.16% 15% 42.04% 42.86% 32.66% | 16-19% | 20% or more ! Total 100% 100% 100% | | 1.14% 6.12% 9.18% 28.41 % 35.71% 50.00% Among those surveyed having an opinion. TipPercent I Tip less than 15% | Tip 15% through 19% | Tip 20% or more Yes, have left without tipping No, have not left without tipping Total 64% 5096 36% 100% 35% 65% 100% 50% 100%