This lesson includes 22 additional questions and 221 additional question variations for subscribers.

# Lesson Worksheet: Grouped Frequency Tables: Estimating the Mean Mathematics

In this worksheet, we will practice estimating the mean using grouped frequency tables.

**Q1: **

A number of teenagers were surveyed on how many days a month they exercise. The results are given below. Complete the table by finding the midpoints of each group.

Days | 0– | 5– | 10– | 15– | 20– | 25– |
---|---|---|---|---|---|---|

Frequency | 3 | 7 | 8 | 6 | 4 | 1 |

Midpoint (Days) | 7.5 | 17.5 |

- A2.5, 12.5, 22.5, 30
- B5, 12.5, 22.5, 27.5
- C2.5, 12.5, 22.5, 27.5
- D2.5, 12.5, 22.5, 25
- E2.5, 15, 22.5, 27.5

**Q2: **

In an extract of a book, the number of words per sentence was counted. Find the missing numbers in the following table.

Number of Words | Frequency | Midpoint | Frequency Midpoint |
---|---|---|---|

1–7 | 15 | 4 | 60 |

8–14 | 20 | ||

15–21 | 45 | 18 | 810 |

22–28 | 47 | 25 | 1,175 |

29–35 | 23 | 32 | 736 |

36–42 | 10 | 39 | 390 |

- A14, 280
- B8, 160
- C12, 240
- D10, 200
- E11, 220

Use the previous table to calculate an estimate for the mean number of words. Give your answer to two decimal places.

**Q3: **

In order to estimate the mean from given grouped data, which of the following is true?

- AWe calculate the upper limit of each class and then use the following rule: sum of .
- BWe calculate the lower limit of each class and then use the following rule: sum of .
- CWe calculate the midpoint of each class and then use the following rule: sum of .
- DWe calculate the midpoint of each class and then use the following rule: sum of .
- EWe calculate the lower limit of each class and then use the following rule: sum of .