Question

akh wants to find the average height of students in the (9^{th}) grade at west high school. so he will use the heights of 20 students in the (9^{th}) grade to find the average height.
answer the questions below.
(a) which unit(s) could be used for the unit of measurement? check all that apply.
□ feet □ pounds □ ounces □ centimeters □ kilograms
(b) which of the procedures below would be the best way to find the average height?
○ randomly pick 20 students from the (9^{th}) grade and measure their heights.
○ randomly pick 20 students from the (9^{th}) grade and have them state their own heights.
○ ask for 20 volunteers from the (9^{th}) grade to state their own heights.
○ measure the heights of 20 volunteers from the (9^{th}) grade.

Explanation:

Part (a)

• Feet: A unit of length, suitable for measuring height.
• Centimeters: A unit of length in the metric system, also suitable for measuring height.
• Pounds: A unit of weight, not length.
• Ounces: A unit of weight (or volume in some contexts), not length.
• Kilograms: A unit of mass, not length.

Part (b)

• Randomly pick 20 students from the \(9^{th}\) grade and measure their heights: This is a random sample. Random sampling helps to avoid bias. Measuring (as opposed to self - reporting) gives more accurate data.
• Ask for 20 volunteers from the \(9^{th}\) grade to state their own heights: Volunteer bias can occur (e.g., only students with certain height characteristics may volunteer), and self - reporting may be less accurate.
• Measure the heights of 20 volunteers from the \(9^{th}\) grade: Volunteer bias can still be an issue.

Answer:

(a) feet, centimeters
(b) Randomly pick 20 students from the \(9^{th}\) grade and measure their heights.