If using the radius, you would multiply the radius by 2*pi, to calculate the circumference, which should be the same as the answer i got.
Answer:
The correct answer is option 'a' : 120 is more than 2.5 standard deviations above the expected value.
Step-by-step explanation:
For an exponential distribution we have
The expected value μ = 80
No of trails n = 200
Thus we have

The deviation is related to expected value and probability as

Thus the values between the given deviation is

Now since 120 successes are out of the range of [62.75,97.25] thus 120 is more than the expected value.
30/8=3.75
So, you need 4 trays, since you can't have 75% of a tray.
Hope this helps
Answer: 180 cookies
Step-by-step explanation: If 1.75 cups of flour is required to make a batch and the bakery used 5.25, the bakery made 3 batches, since 1.75(3) is 5.25. One dozen is 12 cookies, and there are 5 dozen cookies in each batch. If there are 3 batches, then there are 15 dozens of cookies. 15(12) is 180.
Breaking the it down- simplifying