## Introductory Statistics 9th Edition

The ranked data set in increasing order is as follows: 3, 3, 4, 4, 5, 5, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10, 11, 11, 12,12, 16 The values of the three quartiles are: Q1 =the median of the data smaller than Q2 = 5 Q2 = median = (10th+11th) / 2 + (8+8) /2= 8 Q3 =the median of the data larger than Q2 = 11 Interquartile range = Q3-Q1 = 11-5= 6 The value of 4 lies in Q1 since 4 is less than Q1, which is 5. b. the value of the 25th percentile = $(25x20)\div100 = 8th = 7$ c. Percentile rank of 10 = (14/20)x100% = 70% For 70% of the days, the number of new cars sold at a dealership is less than 10 cars.