Question

find the mean of this data set: 1.2, 3.6, 6.6, 4.2, 4.2, 4.3, 7.2
a 4.2
b 4.47
c 5.2
d 31.3

Explanation:

Step1: Sum the data values

The data set is \(1.2, 3.6, 6.6, 4.2, 4.2, 4.3, 7.2\). We sum these values:
\(1.2 + 3.6+6.6 + 4.2+4.2+4.3+7.2\)
\(= (1.2 + 3.6)+(6.6 + 4.2)+(4.2 + 4.3)+7.2\)
\(= 4.8+10.8+8.5+7.2\)
\(= 4.8+10.8 = 15.6\); \(15.6+8.5 = 24.1\); \(24.1 + 7.2=31.3\)

Step2: Count the number of data points

There are \(n = 7\) data points.

Step3: Calculate the mean

The formula for the mean \(\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}\), where \(\sum_{i = 1}^{n}x_{i}=31.3\) and \(n = 7\). So, \(\bar{x}=\frac{31.3}{7}\approx4.47\)

Answer:

B. 4.47