Unit 1: Statistics End of Unit Review

When analyzing numerical data, the best measure of center with NO outlier is: (a)  

• mean
• median
• mode
• range

Answer explanation

The mean. The mean is usually the best measure of center.

If there were an outlier, you would use the median as the best measure of center.

If the data was non-numeric, you would use the mode.

To find the mean of a set of numbers you...

• multiply all the numbers then divide by how many numbers are in the set

• add the numbers together, then divide by how many numbers are in the set

Answer explanation

To find the mean of a set of numbers, you need to add up all of the numbers in the set and then divide the sum by the total number of numbers in the set. This will give you the average or mean of the set.

Find the mean of these numbers:
2, 57, 38, 42, 6

(a)  

Answer explanation

The mean of these numbers is 29.

To find the mean, add all of the numbers together and then divide by the number of numbers (in this case, 5).

2 + 57 + 38 + 42 + 6 = 145. 145 / 5 = 29

What measure of center is best to use when we have outliers?

• mean

• median

• mode

• range

Answer explanation

When dealing with outliers, it is best to use the median as a measure of center. The median is less affected by outliers than the mean, as it is the middle value in a dataset and is not affected by extreme values.

The mean of four numbers is 10.

Three of the numbers are 9, 11 and 7.

What does the 4th number need to be to get a mean of 10?

• 9

• 13

• 11

• 15

Answer explanation

The fourth number needs to be 13 in order to get a mean of 10. This is because the mean is calculated by adding all of the numbers together and then dividing by the number of numbers. In this case, the sum of the four numbers is 9 + 11 + 7 + x, where x is the fourth number. To get a mean of 10, the sum must be equal to 40 (10 x 4). Therefore, the missing number is 13.

At Donald's Donuts the number of donut holes in a bag can vary. Help Donald find the mode.
12,10,10,10,13,12,11,13,10

(a)  

Answer explanation

The mode of this set of numbers is 10, since it appears the most times.

To find the (a)   you add up all the numbers and then divide by how many numbers you have.

• Mean
• Median
• Mode
• Range

Answer explanation

Answer: mean (or average)

To find the ​ (a)   you put all numbers in order from least to greatest and then take the largest number minus the smallest number.

• Range
• Mean
• Median
• Mode

Answer explanation

The range of a set of numbers is the difference between the largest and smallest numbers in the set. To find the range, you need to put all the numbers in order from least to greatest and then subtract the smallest number from the largest number. This will give you the range of the set.

To find the ​ (a)   you put all numbers in order from least to greatest and find the number that is in the middle.

• Median
• Mean
• Mode
• Range

Answer explanation

The median is the middle number in a set of numbers. To find the median, you need to put all the numbers in order from least to greatest. Then, you find the number that is in the middle of the set. If there is an even number of numbers, then you take the average of the two middle numbers.

A data set can have more than one mode.

• True

• False

Answer explanation

A mode is the most frequently occurring value in a data set. A data set can have more than one mode if there are multiple values that occur with the same frequency. For example, if a data set contains the values 1, 2, 2, 2, 3, 3, 3, 4, the modes would be 2 and 3, since both of these values occur more times than the other numbers.