Question

Reference Image
What are the values of the mean, and spread for the dataset shown in the bar graph?

Answer 1

I can't see the image — could you either upload it here or type the bar labels and their frequencies (e.g. value 2: freq 3; value 3: freq 5; …)? Once I have the numbers I can compute the mean and a measure of spread for you.

If you want to compute them yourself, here are the steps and formulas:

1. Identify values (or class midpoints if the bars are intervals) x_i and their frequencies f_i. Let N = sum f_i.

2. Mean (weighted mean for a frequency table):
mean = (Σ x_i f_i) / N

3. Spread — common choices:
- Range = max(x) − min(x)
- Variance (population) = (Σ f_i (x_i − mean)^2) / N
- Variance (sample) = (Σ f_i (x_i − mean)^2) / (N − 1)
- Standard deviation = sqrt(variance)
- Interquartile range (IQR) = Q3 − Q1 (for quartiles use cumulative frequencies)

Notes:
- Use class midpoints if bars are intervals (e.g., class 10–19 midpoint = 14.5).
- Use population formulas if the bars represent the whole population; use sample formulas if they represent a sample.

If you paste the bar values/frequencies or upload the image I’ll compute the mean and whichever spread measure you prefer (standard deviation, variance, range, or IQR).