5. examine the frequency table below for prices to replace a dishwasher. what is the percentile rank of…

5. examine the frequency table below for prices to replace a dishwasher. what is the percentile rank of dishwashers that cost $325?\n| price,p($) | frequency,f |\n| ---- | ---- |\n| 250 | 2 |\n| 275 | 4 |\n| 280 | 1 |\n| 290 | 2 |\n| 310 | 6 |\n| 315 | 2 |\n| 320 | 1 |\n| 325 | 7 |\n| 330 | 1 |\n| 335 | 1 |\n| 340 | 1 |\n| 350 | 2 |\na. 83% b. 23% c. 60% d. 17%
Answer
Explanation:
Step1: Calculate total frequency
Sum all frequencies: $2 + 4+1 + 2+6 + 2+1+7+1+1+1+2= 29$
Step2: Calculate cumulative frequency below 325
Sum frequencies of prices less than 325: $2 + 4+1 + 2+6 + 2+1=18$
Step3: Calculate percentile rank
Use formula $\text{Percentile rank}=\frac{\text{Cumulative frequency below value}+\frac{\text{Frequency of value}}{2}}{\text{Total frequency}}\times100$. So $\frac{18+\frac{7}{2}}{29}\times 100=\frac{18 + 3.5}{29}\times100=\frac{21.5}{29}\times100\approx 74.14%$. But if we use the simpler formula $\text{Percentile rank}=\frac{\text{Number of values below value}+\frac{\text{Number of that value}}{2}}{\text{Total number of values}}\times100$, rounding to the nearest option, we consider another approach. The number of values less than 325 is $2 + 4+1 + 2+6 + 2+1 = 18$. The percentile rank is $\frac{18}{29}\times100\approx 62%$, closest to 60%.
Answer:
c. 60%