Okay, let's recalculate the mean using an assumed mean of 47.
First, let's update the table with the new assumed mean A=47:
| Age Group | Frequency (f) | Class Midpoint (x) | Cumulative Frequency (cf) | Deviation (d=x−47) | fd |
| :-------- | :-------------- | :------------------- | :-------------------------- | :----------------------- | :--- |
| 10-19 | 6 | 14.5 | 6 | -32.5 | -195 |
| 20-29 | 12 | 24.5 | 18 | -22.5 | -270 |
| 30-39 | 15 | 34.5 | 33 | -12.5 | -187.5 |
| 40-49 | 9 | 44.5 | 42 | -2.5 | -22.5 |
| 50-59 | 5 | 54.5 | 47 | 7.5 | 37.5 |
| 60-69 | 2 | 64.5 | 49 | 17.5 | 35 |
| Total | ∑f=49 | | | | ∑fd=−602.5 |
1) Calculate the mean using an assumed mean of 47.
Step 1: Identify the assumed mean (A), sum of frequencies (∑f), and sum of fd (∑fd).
Given assumed mean A=47.
From the updated table, ∑f=49 and ∑fd=−602.5.
Step 2: Apply the formula for the mean using an assumed mean.
xˉ=A+∑f∑fd
Step 3: Substitute the values into the formula and calculate.
xˉ=47+49−602.5
xˉ=47−12.30
xˉ=34.70
The mean using an assumed mean of 47 is 34.70.
That's 2 down. 3 left today — send the next one.