The following data were collected on how many seconds it takes each runner to run one lap around the track:

34 sec, 29 sec., 45 sec. 38 sec. and 52 sec.

If the time for another runner is added to the data and that runner ran the lap in 60 sec., by how much does the mean of the data set change?

Use the lesson notes as needed for help.

1 answer

To find the mean of the original data set, we first need to calculate the sum of all the times:
34 + 29 + 45 + 38 + 52 = 198

Now, to find the mean, we divide the sum by the number of data points:
Mean = 198 / 5 = 39.6 seconds

Now, we will add the time for the additional runner (60 seconds) to the original data set and find the new mean:
198 + 60 = 258

Mean = 258 / 6 = 43 seconds

Therefore, the mean of the data set changed by:
43 - 39.6 = 3.4 seconds

So, the mean of the data set increased by 3.4 seconds when the time for the new runner was added.