Given the data set $4,7,9,10,12$, what is the sample mean?

• A. $8.8$
• B. $8.4$
• C. $9.0$
• D. $8.0$

Answer: (A)

Verified step by step guidance

1. Identify the data set given: 4, 7, 9, 10, 12.
2. Recall that the sample mean \( \bar{x} \) is calculated by summing all the data points and then dividing by the number of data points.
3. Write the formula for the sample mean: \[ \bar{x} = \frac{\sum_{i=1}^n x_i}{n} \] where \( x_i \) are the data points and \( n \) is the number of data points.
4. Calculate the sum of the data points: \[ 4 + 7 + 9 + 10 + 12 \]
5. Count the number of data points, which is 5, and then divide the sum by 5 to find the sample mean.