Answer is B.
We see the center lines are 80 and 85 as stated.
A is wrong because the range of class 2 is less.
C is wrong; class 2 has a minimum of 50
D is wrong; class 2 has a smaller interquartile range, which is the width of the boxes.
Answer: 100pi
Step-by-step explanation:
Answer:

And replacing we got:

The probability that a randomly selected barber needs at least 14 minutes to complete the haircut is 0.5714
Step-by-step explanation:
We define the random variable of interest as x " time it takes a barber to complete a haircuts" and we know that the distribution for X is given by:

And for this case we want to find the following probability:

We can find this probability using the complement rule and the cumulative distribution function given by:

Using this formula we got:

And replacing we got:

The probability that a randomly selected barber needs at least 14 minutes to complete the haircut is 0.5714
Rounded to the nearest whole number would be 426
1/2*5 = 2.5 ~ 3 (round-off)
1/3* 10 = 3.33 ~ 3