Final answer:
Without the specific dot plot data, we cannot calculate the mean and median for 5th or 7th graders' television-watching habits. The details provided do not allow for an actual computation of these measures of central tendency. Definitions for median and mean are given for theoretical understanding.
Step-by-step explanation:
We do not have the specific data required to directly calculate the mean and median for the 5th and 7th graders watching television each week. Therefore, to accurately provide these statistics, we would need a dot plot or a data set which shows the number of hours the students spend watching TV. Once we have this data, we can calculate the mean by adding up all the values and dividing by the number of observations. The median is the middle value when the data points are ordered from least to greatest.
Based on the information we have:
- The 5th-grade mean cannot be determined without specific data.
- The 7th-grade median cannot be determined without specific data.
- For part c, the reference to 'Part b' seems to be missing the context, and '2.8 minutes' doesn't match the question regarding hours spent by 5th graders watching television.
- Part d appears to be repeated and should be instead the mean or median for 7th graders which, again, cannot be answered without the data.
For theoretical understanding, if the mean is said to be larger than the median in a given sample, this generally indicates a right-skewed distribution where there are some larger outliers affecting the mean. In the context of the 7th graders watching TV, if their data were skewed, then it could be that a few students watched significantly more TV than their peers.
The section of the question that includes additional exercises appears to be unrelated to the initial question asked by the student.