the histogram shown summarizes the responses of 100 people when asked, \what was the price of the last meal…

the histogram shown summarizes the responses of 100 people when asked, \what was the price of the last meal you purchased?\ based on the histogram, which of the following could be the interquartile range of the prices? a $40 b $21 c $10 d $5 e $3

the histogram shown summarizes the responses of 100 people when asked, \what was the price of the last meal you purchased?\ based on the histogram, which of the following could be the interquartile range of the prices? a $40 b $21 c $10 d $5 e $3

Answer

Explanation:

Step1: Calculate cumulative frequencies

First, find the cumulative frequencies for each price - point. The total number of data points is $n = 100$.

Price ($) Frequency Cumulative Frequency
5 8 8
9 13 8 + 13=21
13 11 21+11 = 32
17 14 32 + 14=46
21 8 46+8 = 54
25 5 54+5 = 59
29 3 59+3 = 62
33 2 62+2 = 64
37 0 64+0 = 64
41 1 64+1 = 65
45 1 65+1 = 66

Step2: Find the first quartile ($Q_1$) position

The position of $Q_1$ is $L_{Q_1}=\frac{n + 1}{4}=\frac{100+1}{4}=25.25$. The value of $Q_1$ lies in the class where the cumulative - frequency first exceeds 25.25. Looking at the cumulative frequencies, 25.25 lies in the class with a price of $9$ (since the cumulative frequency up to the class with price $9$ is 21 and up to the class with price $13$ is 32). We can approximate $Q_1$ using the formula for the first quartile in a grouped data set (if needed, but for a rough estimate, we know it's in the $9$ - $13$ range and closer to $9$). A simple estimate is that $Q_1\approx9$.

Step3: Find the third quartile ($Q_3$) position

The position of $Q_3$ is $L_{Q_3}=\frac{3(n + 1)}{4}=\frac{3\times(100 + 1)}{4}=75.75$. The value of $Q_3$ lies in the class where the cumulative - frequency first exceeds 75.75. Looking at the cumulative frequencies, 75.75 lies in the class with a price of $21$ (since the cumulative frequency up to the class with price $17$ is 46 and up to the class with price $21$ is 54). A simple estimate is that $Q_3\approx21$.

Step4: Calculate the inter - quartile range (IQR)

The inter - quartile range is $IQR = Q_3-Q_1$. $IQR=21 - 9=12$. The closest value to 12 among the given options is $10$.

Answer:

C. $10$