Final answer:
The mean change in the data set cannot be directly calculated from the final values provided. We would need the actual change values between each data point to calculate the mean change accurately. From the information given, we can only approximate or assume that the closest answer provided could be an approximation.
Step-by-step explanation:
The question is asking us to calculate the mean change in a given data set. To find the mean change, we need to sum up all of the changes in the data set and then divide by the total number of changes.
Looking at the data set provided (86, 87, 90, 89, 88, 88, 88), the first step is to calculate the total sum of these values, which equals 616. The number of data values is 7. We then divide the total sum by the number of data points to find the mean:
Total sum of data values = 86 + 87 + 90 + 89 + 88 + 88 + 88 = 616
Number of data values = 7
Mean = Total sum of data values / Number of data values
Mean = 616 / 7
Mean = 88
Since all the individual changes have already been averaged into this single mean, we cannot directly calculate the mean change from this information. However, if we were given the actual changes rather than the final values, we could have summed those changes and divided by 7 to find the mean change. As it stands, option B (0.714) seems like a reasonable approximation by judging the given answer choices and considering a rough estimate of differences among the data points, but we would require the actual change values to compute an exact mean change.