The race speeds for the top eight cars in a 200-mile race are listed below. use the range rule of thumb
to estimate the standard deviation. round results to the nearest tenth.
185.9 179.5 189.2 176.7 1758 188.7. 188.3 177.9

The standard deviation is about 3.6.

Step-by-step explanation:

According to the Range Rule of Thumb  : The range is about four times the standard deviation.

i.e.     (i)

Given , The race speeds for the top eight cars in a 200-mile race are :

185.9 179.5 189.2 176.7 175.8 188.7. 188.3 177.9

Here , minimum speed =  175.8 and maximum speed = 189.2

Range = maximum speed - minimum speed

i.e. R = 189.2-175.8 =13.4

from (i),

Hence, the standard deviation is about 3.6.