86 , 83 , 98 , 99 , 81 , 86 , 95 , 84 , 79 , 90

There are 10 observations, so the median is the mean of the two middle numbers of the arranged set of data. Splitting the observations either side of the median gives two groups of observations. The median of the lower half of data is the lower or first quartile. The median of the upper half of data is the upper or third quartile.

The median of the lower half of data is the lower or first quartile

The median of the upper half of data is the upper or third quartile

Arrange the terms in ascending order.

79,81,83,84,86,86,90,95,98,99

The median is the middle term in the arranged data set. In the case of an even number of terms, the median is the average of the two middle terms.

86+862

Remove parentheses.

86+862

Cancel the common factor of 86+86 and 2.

Factor 2 out of 86.

2⋅43+862

Factor 2 out of 86.

2⋅43+2⋅432

Factor 2 out of 2⋅43+2⋅43.

2⋅(43+43)2

Cancel the common factors.

Factor 2 out of 2.

2⋅(43+43)2(1)

Cancel the common factor.

2⋅(43+43)2⋅1

Rewrite the expression.

43+431

Divide 43+43 by 1.

43+43

43+43

43+43

Add 43 and 43.

86

Convert the median 86 to decimal.

86

86

The lower half of data is the set below the median.

79,81,83,84,86

The median is the middle term in the arranged data set.

83

Find the Lower or First Quartile 86 , 83 , 98 , 99 , 81 , 86 , 95 , 84 , 79 , 90