Question

The line plot shows the number of phone calls made in one day by students in​ Dorothy’s class.
Number of Phone Calls
3
4
5
6
7
8
9
10
11
12
13
14
15



A dot plot labeled Results of Coin Tosses has a horizontal axis labeled Number of ~sideC from 5 to 15 in increments of 1. The graph consists of a series of plotted points from left to right. The number of dots on each horizontal axis label are as follows, where the label is listed first and the number of dots is listed second: 5, 1; 6, 1; 7, 2; 8, 2; 9, 5; 10, 4; 11, 5; 12, 2; 13, 2; 14, 0; 15, 1.
Question content area bottom
Part 1
Based on the information in the line​ plot, what is the probability a student
chosen at random made 12 or 13 phone calls that​ day?
A.StartFraction 4 Over 25 EndFraction
StartFraction 4 Over 25 EndFraction
B.StartFraction 9 Over 22 EndFraction
StartFraction 9 Over 22 EndFraction
C.StartFraction 11 Over 20 EndFraction
StartFraction 11 Over 20 EndFraction
D.five sixths
five sixths

Answer 1

To find the probability that a randomly chosen student made 12 or 13 phone calls, we need to first determine the total number of students and how many students made either 12 or 13 phone calls based on the data provided.

From the given dot plot:

- Number of students making 12 phone calls: 2
- Number of students making 13 phone calls: 2

So, the total number of students who made 12 or 13 phone calls is:
\( 2 + 2 = 4 \)

Now, we need to calculate the total number of students. Looking at the data, we can sum the dots (which represent students) for all the phone calls:

- 5: 1
- 6: 1
- 7: 2
- 8: 2
- 9: 5
- 10: 4
- 11: 5
- 12: 2
- 13: 2
- 14: 0
- 15: 1

Adding these up:

1 + 1 + 2 + 2 + 5 + 4 + 5 + 2 + 2 + 0 + 1 = 25

The total number of students is 25.

Now we can calculate the probability that a randomly chosen student made either 12 or 13 phone calls:

\[
P(12 \text{ or } 13) = \frac{\text{Number of students making 12 or 13 calls}}{\text{Total number of students}} = \frac{4}{25}
\]

Therefore, the answer is:

**A. \(\frac{4}{25}\)**