Question

select the correct answer. the dot - plot shows the highest daily temperature recorded in a city each year for the past 15 years. what is the interquartile range of the data? highest daily temperatures temperature (°f) a. 97 b. 4 c. 98 d. 6

Explanation:

Step1: Order the data

First, we assume the data points from the dot - plot represent the highest daily temperatures. Let's list them out.

Step2: Find the first quartile ($Q_1$)

Arrange the data in ascending order. Since there are 15 data points, the position of $Q_1$ is $\frac{15 + 1}{4}=4$th value in the ordered data set.

Step3: Find the third quartile ($Q_3$)

The position of $Q_3$ is $3\times\frac{15 + 1}{4}=12$th value in the ordered data set.

Step4: Calculate the inter - quartile range (IQR)

$IQR=Q_3 - Q_1$.
Let's assume the ordered data set from the dot - plot: 94, 94, 94, 95, 95, 97, 98, 98, 98, 98, 98, 99, 99, 99, 100.
The 4th value ($Q_1$) is 95 and the 12th value ($Q_3$) is 99.
$IQR = 99-95=4$

Answer:

B. 4