please explain how the answers were calculated

1.

The mean,=nx=613+245+51+91+301+144=6845=140.83

2. The median of the ungrouped data is obtained by arranging the data in either ascending or descending order and identifying the observation at the middle;

13, 51, 91, 144, 245, 301

Median = (91+144)/2=117.5

3.p40=10040(6+1)=2.8thitem from the arranged from of data, 2.8 is close to the third item, so the 40th percentile is 91.

4. The range is obtained by subtracting the largest observation from the least observation.

Range=301-13=288

5.Standard deviation is the square root of the variance,

s=s2=n1(XX)2=510920.25+4422.25+702.25+702.25+16256.25+33672.25=115.48