Question

Please can someone do this for me? thanks alot x

Answer 1

Sarah's mean = 70.9

Katie's mean = 78.9

Sarah's range = 15

Katie's range = 25

The mean shows that on average Sarah was 8 seconds faster than Katie. The range shows that Sarah was more consistent with her times. Katie had a larger spread of times which shows she was less consistent.

Explanation:

Identifying the mean time for Katie and Sarah

The mean ( average ) is equal to the sum of the numbers in the data set ( the sum of the swimming times ) divided by the number of values in the data set ( which is given as 10 )

Mean for Sarah : Sum of her swimming times : 79 + 70 + 68 + 75 + 69 + 64 + 69 + 75 + 64 + 76 = 709

Number of values = 10

So mean = 709 / 10 = 70.9 seconds.

Mean for Katie : Sum of her swimming times : 79 + 79 + 76 + 81 + 89 + 76 + 64 + 85 + 82 + 78 = 789

number of values = 10

so mean = 789 / 10 = 78.9

Using this information we can identify what the first to blanks are. The mean shows that on average Sarah was ___ seconds ____ than Katie.

The mean time for Sarah was 70.9 seconds and the mean time for Katie was 78.9 seconds. So on average Sarah was faster and by 8 seconds ( which can be found by subtracting Sarah's mean from Katie's )

Identifying the range

The range is equal to the largest value ( longest swim time ) subtracted by the smallest value ( or quickest swim time )

Range for Sarah : Sarah's highest swim time is 79 seconds and her lowest is 64 seconds.

So her range = 79 - 64 = 15 seconds

Range for Katie : Katie's highest swim time is 89 seconds and her lowest time is 64 seconds

So her range = 89 - 64 = 25

Using this information we can fill out the remaining blanks.

The range shows that ____ was more consistent with her times. ___ had a larger spread of times which shows she was ____ consistent.

The higher the range the less consistent you are vise versa. Katie had a larger range hence, Sarah was more consistent and Katie was less consistent.

Answer 2

Learning Objective: Use the mean and range to compare the spread and averages.

a) Sarah Mean = 70.9, Katie Mean = 78.9

b) Sarah Range = 15, Katie Range = 25

c) Sentences

- The mean shows, on average, Sarah was 8 seconds quicker than Katie.

- The range shows that Sarah was more consistent with her times. Katie had a larger spread of times which shows she was less consistent.

Explanation:

Given:

Sarah's Data Set:

• 79, 70, 68, 75, 69, 64, 69, 75, 64, 76

Katie's Data Set:

• 79, 79, 76, 81, 89, 76, 64, 85, 82, 78

To Find:

• The mean and range of both data sets separately.

Work:

The mean of a data set is commonly known as the average. You find the mean by taking the sum of all the data values and dividing that sum by the total number of data values. The formula for the mean of a population is
`\mu = \frac{{\sum}x}{N}`.

The formula for the mean of a sample is
`\bar{x} = \frac{{\sum}x}{n}`.

Both of these formulas use the same mathematical process: find the sum of the data values and divide by the total. For the data values given above, the solution is:
`(709)/(10) = 70.9`

Therefore, the mean of Sarah's data set is 70.9.

For Katie's Data Set,
`(789)/(10) = 78.9`.

Therefore, the mean of Katie's data set is 78.9.

To fill in the summary, we have to use the data we just calculated.

That summary can be found in the answer section.