1. A school administrator sends out grade school students tosell boxes of candy to raise funds. Below is a selection of fourstudents and the mean number of boxes they sold over a weekend. Theadministrator wants to calculate the average number of boxes soldacross students, but wants to weight this by the number of nearbyhouses (because students with more houses nearby will sell moreboxes). For these data, what is the weighted mean?
Mean Candy sold | 5 | 4 | 18 | 10 |
Number of nearby houses | 3 | 4 | 12 | 9 |
2.
Number of songs | Proportion |
10 | 0.1 |
15 | 0.14 |
20 | 0.15 |
25 | 0.11 |
30 | 0.13 |
35 | 0.16 |
40 | 0.09 |
45 | 0.07 |
50 | 0.05 |
What is the average expected number of songs from this sample?(the mean of the probability distribution)
3.
Number of songs | Proportion |
10 | 0.1 |
15 | 0.14 |
20 | 0.15 |
25 | 0.11 |
30 | 0.13 |
35 | 0.16 |
40 | 0.09 |
45 | 0.07 |
50 | 0.05 |
What is the standard deviation of the number of songs from thissample? (the SD of the probability distribution)
4.
| Intervals | Frequency | Cumulative Percent |
| 10-20 | 1 | 3 |
| 21-30 | 3 | 13 |
| 31-40 | 7 | 35 |
| 41-50 | 10 | 68 |
| 51-60 | 8 | 94 |
| 61-70 | 2 | 100 |
What number is at the 55th percentile? (You may round to a wholenumber for the answer)
