At one high school, students can run the 100-yard dash in an average of 15.2 seconds with a standard deviation of .9 seconds. The times are very closely approximated by a normal curve. Find the percent of times that are indicated. Round to the nearest whole percent.
-Between 17 and 17.9 seconds
A) $14 \%$
B) $16 \%$
C) $2 \%$
D) $1 \%$

Question

Quizplus · Accepted Answer

To find the percentage of times between 17 and 17.9 seconds, calculate the z-scores for 17 and 17.9 using the mean (15.2) and standard deviation (0.9). The z-score for 17 is (17-15.2)/0.9 ≈ 2, and for 17.9 is (17.9-15.2)/0.9 ≈ 3. Using the standard normal distribution table, the area between these z-scores is approximately 2%.

At One High School, Students Can Run the 100-Yard Dash 14%14 \%14%

At One High School, Students Can Run the 100-Yard Dash $14 \%$