Solution: We are given:
[tex]Range =2.76[/tex]
[tex]Standard-deviation=0.807[/tex]
Now let's find the estimated value of standard deviation using the range rule of thumb. According to range rule of thumb, the estimate of standard deviation is:
[tex]S\approx \frac{2.76}{4}= 0.690[/tex]
Therefore the estimated standard deviation is 0.690
is this an acceptable approximation?
Answer: c. Yes, because the error of the range rule of thumb's approximation is less than 15%.
Explanation:
The difference between estimated standard deviation and actual standard deviation is:
0.807 - 0.690 = 0.117
Now let's find the percentage of error
[tex]\frac{0.117}{0.807} \times 100= 14.50\%[/tex].
Therefore, the error of the range rule of thumb's approximation is less than 15%.