Question

below are iq scores from 30 randomly selected adults. { 78, 82, 88, 88, 89, 93, 97, 98, 98, 98, 100, 101, 101, 102, 103, 104, 106, 106, 107, 109, 110, 115, 116, 118, 118, 119, 119, 122, 128, 130 }. first, give the mean of the data set.

Explanation:

Step1: Recall mean formula

The mean $\bar{x}$ of a data - set $x_1,x_2,\cdots,x_n$ is given by $\bar{x}=\frac{\sum_{i = 1}^{n}x_i}{n}$, where $n$ is the number of data points and $\sum_{i = 1}^{n}x_i$ is the sum of the data points. Here, $n = 30$.

Step2: Calculate the sum of data points

$\sum_{i=1}^{30}x_i=78 + 82+88+88+89+93+97+98+98+98+100+101+101+102+103+104+106+106+107+109+110+115+116+118+118+119+119+122+128+130=3120$.

Step3: Calculate the mean

$\bar{x}=\frac{\sum_{i = 1}^{30}x_i}{30}=\frac{3120}{30}=104$.

Answer:

104