Question

seventy-five students randomly selected from the junior class at a high school were given a survey asking how much time they spent studying for a math test. assume the population is normally distributed.

the population is
all juniors at the high school

the sample is
the seventy-five juniors selected

according to the survey, the average amount of time spent studying for a math test was 35 minutes, with a standard deviation of 10 minutes.

what range would you expect 95% of the samples study times to be between if the sample was approximately normal?

• 25-45 minutes
• 10-35 minutes
• 15-55 minutes
• 5-65 minutes

Explanation:

Identify the given parameters

Using the Empirical Rule knowledge point

$$
LATEXBLOCK0
$$

Apply the Empirical Rule for 95% interval

Using the Empirical Rule knowledge point

$$
LATEXBLOCK1
$$

Match the interval to the options

Using the Empirical Rule knowledge point

$$ \text{Range} = 15\text{--}55\text{ minutes} $$

Answer:

• 25–45 minutes
• 10–35 minutes
• 15–55 minutes (Correct answer)
• 5–65 minutes