74 , 1 , 23 , 45

There are 4 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.

23,45,1,74

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.

45+12

Remove parentheses.

45+12

Simplify the numerator.

Write 1 as a fraction with a common denominator.

45+552

Combine the numerators over the common denominator.

4+552

Add 4 and 5.

952

952

Multiply the numerator by the reciprocal of the denominator.

95⋅12

Multiply 95⋅12.

Multiply 95 and 12.

95⋅2

Multiply 5 by 2.

910

910

Convert the median 910 to decimal.

0.9

0.9

The upper half of data is the set above the median.

1,74

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.

1+742

Remove parentheses.

1+742

Simplify the numerator.

Write 1 as a fraction with a common denominator.

44+742

Combine the numerators over the common denominator.

4+742

Add 4 and 7.

1142

1142

Multiply the numerator by the reciprocal of the denominator.

114⋅12

Multiply 114⋅12.

Multiply 114 and 12.

114⋅2

Multiply 4 by 2.

118

118

Convert the median 118 to decimal.

1.375

1.375

Find the Upper or Third Quartile 7/4 , 1 , 2/3 , 4/5