Question

Keith wants to find the average height of students in the 9th grade at Washington High School. So he will use a sample of students in the 9th grade to find the average height. (a)Which unit(s) could be used for the unit of measurement? Check all that apply. Feet minutes Centimeters Inches Seconds(b)Which of the procedures below would be the best way to find the average height? Randomly pick 50 students from the 9th grade and measure their height Randomly pick 5 students from the 9th grade and have them state their own height Ask for 50 volunteers from the 9th grade to state their own height Measure the heights of 5 volunteers from the 9th grade

Answer 1

Keith wants to find the average height of students in the 9th grade at Washington High School.

(a) We are asked to determine which units could be used for the unit of measurement.

Recall that the height can be measured in various units

Feet, inches, and centimeters are all possible units for measuring height.

The other options are incorrect since they are the units of time (minutes and seconds)

Therefore, the correct choices are

Feet

Centimeters

Inches

(b) Which of the procedures below would be the best way to find the average height?

Recall that a larger sample size is always preferred since it will have a smaller standard error.

Also, random sampling is always preferred since it will have less bias.

So, the best procedure will be

"Randomly pick 50 students from the 9th grade and measure their height"

The other two options are not best because they have a smaller sample size.

Also, one option says to ask for 50 volunteers which is also not best since it will be biased. (because it is not random)