People tend to be more generous after receiving good news. Are they less generous after receiving bad news? The average tip left by adult Americans is 19%. Say that a server gives 20 patrons of a restaurant a message on their bill warning them that tomorrow's weather will be bad and record the percentage tip they leave. The tips as a percentage of the total bill are given in the table. Tips (percentage) , 18.0 19.1 19.2 18.8 18.4 19.0 18.5 16.1 16.8 18.2 14.0 17.0 13.6 17.5 20.0 20.2 18.8 18.0 23.2 19.4 Suppose that percentage tips are Normal with or = 1.8. Click to download the data in your preferred format. CSV Excel JMP MacText Minitabl418 Minitab18+ PCText R SPSS TI Crunchlt! Information about the NAEP test can be found online at httpsn'r'www.nationsmpnrtcurd.guv. SOLVE: We have a random sample of n = 20 customers and were told to assume tips have a Normal distribution. Find x. Give your answer to two decimal places. @ Macmillan Learning X = % Incorrect Find the z statistic. Give your answer to two decimal places. -1.72 Z = Incorrect Using the software of your choice or Table A, find the P-value. Give your answer to four decimal places. 0.0508 P-value: Incorrect