11) a medical research team studied the ages ...
11) a medical research team studied the ages of patients who had strokes caused by stress. the ages of 34 patients who suffered stress strokes were as follows. 29 30 36 41 45 50 57 61 28 50 36 58 60 38 36 47 40 32 58 46 61 40 55 32 61 56 45 46 62 36 38 40 50 27 construct a frequency distribution for these ages. use 8 classes beginning with a lower class limit of 25. age | frequency
Answer
# Explanation:
## Step1: Calculate class - width
The range of data is the difference between the maximum and minimum values. The maximum value in the data set is 62 and the minimum is 27. Range = 62 - 27=35. We want 8 classes. Class - width $w=\frac{\text{Range}}{\text{Number of classes}}=\frac{35}{8}\approx4.375$. We round up to 5.
## Step2: Define class intervals
Starting with a lower - class limit of 25, the class intervals are: 25 - 29, 30 - 34, 35 - 39, 40 - 44, 45 - 49, 50 - 54, 55 - 59, 60 - 64.
## Step3: Count frequencies
For the class 25 - 29: The values 27, 28, 29 are in this class, so frequency = 3.
For the class 30 - 34: The values 30, 32, 32, 32 are in this class, so frequency = 4.
For the class 35 - 39: The values 36, 36, 36, 36, 38, 38 are in this class, so frequency = 6.
For the class 40 - 44: The values 40, 40, 40 are in this class, so frequency = 3.
For the class 45 - 49: The values 45, 45, 46, 46, 47 are in this class, so frequency = 5.
For the class 50 - 54: The values 50, 50, 50 are in this class, so frequency = 3.
For the class 55 - 59: The values 55, 56, 57, 58, 58 are in this class, so frequency = 5.
For the class 60 - 64: The values 60, 61, 61, 61, 62 are in this class, so frequency = 5.
# Answer:
| Age | Frequency |
| ---- | ---- |
| 25 - 29 | 3 |
| 30 - 34 | 4 |
| 35 - 39 | 6 |
| 40 - 44 | 3 |
| 45 - 49 | 5 |
| 50 - 54 | 3 |
| 55 - 59 | 5 |
| 60 - 64 | 5 |