OpenUp 6th Math 8.9 Practice Problems and Vocab

The ___ is another name for the mean of a data set.

For the data set 3, 5, 6, 8, 11, 12, the ____ is 7.5.

The ___ is one way to measure the center of a data set. We can think of it as a balance point. 

How do you find the mean/average of a data set?

• Add up all the numbers in the data set. Then, divide by how many numbers there are.

• Add up all the numbers in the data set. Then, multiply by how many numbers there are.

• Multiply all the numbers in the data set. Then, divide by how many numbers there are.

• Multiply all the numbers in the data set. Then, multiply by how many numbers there are.

A preschool teacher is rearranging four boxes of playing blocks so that each box contains an equal number of blocks. Currently Box 1 has 32 blocks, Box 2 has 18, Box 3 has 41, and Box 4 has 9.

Select all the ways he could make each box have the same number of blocks.

• Remove all the blocks and make four equal piles of 25, then put each pile in one of the boxes.

• Remove 7 blocks from Box 1 and place them in Box 2.

• Remove 21 blocks from Box 3 and place them in Box 4.

• Remove 7 blocks from Box 1 and place them in Box 2, and remove 21 blocks from Box 3 and place them in Box 4.

• Remove 7 blocks from Box 1 and place them in Box 2, and remove 16 blocks from Box 3 and place them in Box 4.

In a round of mini-golf, Clare records the number of strokes it takes to hit the ball into the hole of each green. She said that, if she redistributed the strokes on different greens, she could tell that her average number of strokes per hole is 3.

Explain how Clare is correct.

Three sixth-grade classes raised $25.50, $49.75, and $37.25 for their classroom libraries. They agreed to share the money raised equally. What is each class’s equal share? Explain or show your reasoning.

In her English class, Mai’s teacher gives 4 quizzes each worth 5 points. After 3 quizzes, she has the scores 4, 3, and 4. What does she need to get on the last quiz to have a mean score of 4? Explain or show your reasoning.