What is the first quartile of the data set? {51, 42, 46, 53, 66, 70, 90, 70} A-48.5 B-59.5 C-61 D-80

The first quartile is the middle of the lower half of the data.

To find this you must:

1. Order the data from least to greatest.

42, 46, 51, 53, | 66, 70, 70, 90

2. Next, find where the middle of the data set it - see the line above

3. Look at the lower half of the data - see the bold half above.

4. Find the middle of that half - see the underlined numbers above.

5. Find the middle of the 2 numbers

(46 + 51)

2 = 48.5

48.5 is the 1st quartile.