Question

1. the time in minutes taken by each adult in a sample to solve a problem is displayed in the graph below. based on what you see in this graph, approximately what percentage of the sample took at least 15 minutes to solve the problem? a. 48.9% b. 15.6% c. 20.0% d. 51.1% e. it is impossible to answer this question without more information.

Explanation:

Step1: Calculate total frequency

Sum up all the frequencies. $1 + 1+3 + 3+2+5+7+9+9+5 = 45$

Step2: Calculate frequency of those who took at least 15 minutes

Sum up frequencies for time intervals 15 - 17, 17 - 19, 19 - 21. $9+9+5=23$

Step3: Calculate percentage

Use the formula $\text{Percentage}=\frac{\text{Frequency of at - least 15 minutes}}{\text{Total frequency}}\times100\%$. So, $\frac{23}{45}\times 100\%\approx 51.1\%$

Answer:

D. 51.1%