Question

david wants to find the average height of students in the 11th grade at washington high school. so he will use a sample of students in the 11th 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. hours centimeters seconds inches feet (b) which of the procedures below would be the best way to find the average height? randomly pick 5 students from the 11th grade and have them state their own heights. randomly pick 50 students from the 11th grade and measure their heights. measure the heights of 5 volunteers from the 11th grade. ask for 50 volunteers from the 11th grade to state their own heights.

Explanation:

Part (a)

Step1: Analyze each unit

• Hours: A unit of time, not length.
• Centimeters: A unit of length.
• Seconds: A unit of time, not length.
• Inches: A unit of length.
• Feet: A unit of length.

Part (b)

Step1: Consider sample size and measurement method

• Randomly pick 5 students from the \(11^{th}\) grade and have them state their own heights: A very small sample size (\(n = 5\)) may not be representative. Also, self - reported heights can be inaccurate.
• Randomly pick 50 students from the \(11^{th}\) grade and measure their heights: A larger sample size (\(n=50\)) is more likely to be representative of the \(11^{th}\) - grade population. Measuring (as opposed to self - reporting) gives more accurate data.
• Measure the heights of 5 volunteers from the \(11^{th}\) grade: A small sample size (\(n = 5\)) and volunteers may not be a random (and thus representative) sample.
• Ask for 50 volunteers from the \(11^{th}\) grade to state their own heights: Volunteers may not be a random sample and self - reported data can be inaccurate.

Answer:

Part (a)

Centimeters, inches, feet.

Part (b)

Randomly pick 50 students from the \(11^{th}\) grade and measure their heights.