Question-44

Mean

Let the sample mean of a set of \(20\) data points be \(30\). If it is discovered that a data point having value \(25\) was incorrectly entered as \(15\), what should be the revised value of the sample mean\(?\) Enter the answer correct to one decimal place.

\(\overline{x} = \dfrac{\sum_{i=1}^{n}x_i}{n}\)

\(\sum_{i=1}^{n}x_i = n\overline{x}\)

Find the correct \(\sum_{i=1}^{n}x_i\) and calculate the mean.

30.5