Question

milan wants to find the average time it takes lincoln high school students to run a lap around the track. so he will consider a sample of students to find the average time.
answer the questions below.
(a) which unit(s) could be used for the unit of measurement? check all that apply.
□ pounds □ hours □ seconds □ minutes □ grams
(b) which of the procedures below would be the best way to find the average time?
○ randomly pick 32 students to run a lap around the track and measure their times.
○ randomly pick 6 students to run a lap around the track and have them state their own times.
○ ask for 32 volunteers to run a lap around the track and have them state their own times.
○ measure the times of 6 volunteers who run a lap around the track.

Explanation:

Part (a)

To determine appropriate units for measuring time to run a lap, we analyze each option:

• Pounds: Unit of weight, not time. Eliminate.
• Hours: Valid for time (though a lap is unlikely to take hours, but still a time unit).
• Seconds: Standard unit for short durations like a lap.
• Minutes: Valid for time (a lap could take minutes).
• Grams: Unit of mass, not time. Eliminate.

So the valid time units are hours, seconds, minutes.

For a representative sample:

• Random sampling is better than volunteer sampling (volunteers may be biased, e.g., more athletic).
• Larger sample size (32 vs. 6) gives more accurate results.
• Measuring times (vs. self - reporting) avoids self - reporting bias (students might misreport).

So "Randomly pick 32 students to run a lap around the track and measure their times" is best.

Answer:

• hours
• seconds
• minutes

Part (b)