Final answer:
To find the class width for a frequency table with seven classes, calculate the range of the dataset and divide by the number of classes, rounding up if necessary. The class width in this case is approximately 13. To find the class limits, start with the lowest value and add the class width successively to create seven intervals.
Step-by-step explanation:
In order to find the class width for a frequency table with seven classes given a data set with a low value of 40 and a high value of 129, we first calculate the range. The range is 129 - 40 = 89. To find the number of classes, we divide the range by the number of classes and then round up to ensure each data point fits into a class. Therefore, the class width is ≈ 13 when rounded up (89 / 7 = 12.71, rounded up to 13).
Now, to find the class limits for the frequency table with seven classes with the class width of 13, we start at 40. The first class would be 40-52, the next one would be 53-65, continuing in this fashion until we create seven intervals. The class limits are:
- 40 - 52
- 53 - 65
- 66 - 78
- 79 - 91
- 92 - 104
- 105 - 117
- 118 - 130
Note that although the highest value is 129, we list the upper limit of the last class as 130 to maintain a class width of 13.