525, 650, 539, 643, 764, 539, 687

What is the interquartile range of these numbers?

To find the interquartile range, we first need to find the first quartile (Q1) and third quartile (Q3).

To find Q1:
1. Arrange the numbers in ascending order: 525, 539, 539, 643, 650, 687, 764
2. Determine the position of Q1 using the formula: (n+1)/4, where n is the total number of data points.
In this case, n = 7, so (7+1)/4 = 8/4 = 2.
Q1 is the second number in the list, which is 539.

To find Q3:
1. Determine the position of Q3 using the formula: 3(n+1)/4.
3(7+1)/4 = 3(8)/4 = 3(2) = 6.
Q3 is the sixth number in the list, which is 687.

Now that we have Q1 = 539 and Q3 = 687, we can find the interquartile range:
Interquartile Range = Q3 - Q1 = 687 - 539 = 148.

Therefore, the interquartile range of these numbers is 148.