Chau wants to find the average height of students in the \( 11^{\text {th }} \) grade at Northside High School. So he will use the heights of 35 students in the \( 11^{\text {th }} \) 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. \( \square \) pounds \( \square \) ounces \( \square \) centimeters \( \square \) grams (b) Which of the procedures below would be the best way to find the average height? Ask for 35 volunteers from the \( 11^{\text {th }} \) grade to state their own heights. Randomly pick 35 students from the \( 11^{\text {th }} \) grade and measure their heights. Randomly pick 35 students from the \( 11^{\text {th }} \) grade and have them state their own heights.

Let's analyze the problem step by step. ### Part (a): Units of Measurement We need to determine which units could be used for measuring height. The options provided are: - Pounds - Ounces - Centimeters - Grams **Analysis of Units:** - **Pounds**: This is a unit of weight, not height. - **Ounces**: This is also a unit of weight, not height. - **Centimeters**: This is a unit of length and is appropriate for measuring height. - **Grams**: This is a unit of weight, not height. **Conclusion for Part (a):** The only suitable unit for measuring height is: - \( \square \) centimeters ### Part (b): Best Procedure to Find Average Height Now, we need to evaluate the best procedure to find the average height of the students. The options are: 1. Ask for 35 volunteers from the \( 11^{\text{th}} \) grade to state their own heights. 2. Randomly pick 35 students from the \( 11^{\text{th}} \) grade and measure their heights. 3. Randomly pick 35 students from the \( 11^{\text{th}} \) grade and have them state their own heights. **Analysis of Procedures:** 1. **Volunteers stating their own heights**: This could lead to bias, as those who volunteer may not represent the entire population of students. 2. **Randomly picking students and measuring their heights**: This is the best method as it ensures a random sample and accurate measurement, minimizing bias. 3. **Randomly picking students and having them state their own heights**: This could also lead to inaccuracies, as students may not accurately report their heights. **Conclusion for Part (b):** The best procedure to find the average height is: - Randomly pick 35 students from the \( 11^{\text{th}} \) grade and measure their heights. ### Final Answers: (a) \( \square \) centimeters (b) Randomly pick 35 students from the \( 11^{\text{th}} \) grade and measure their heights.