3. Suppose that the volume of sound generated by heavy machinery in a factory is normally distributed, with a mean of 50 dB and a standard deviation of 10 dB.
(a) What is the probability that the volume of sound measurement at a particular time
(1) between 45 and 55 dB?
(2) between 40 and 60 dB?
(3) above 80 dB?
(b) 20% of the sound volumes will be below what value?
(c) There is a 99% chance that the sound volume will be below what value?
If measurements are taken twice an hour during an eight hour period,
(d) what is the probability that the average volume of sound measurement for th

Question

3. Suppose that the volume of sound generated by heavy machinery in a factory is normally distributed, with a mean of 50 dB and a standard deviation of 10 dB.
(a) What is the probability that the volume of sound measurement at a particular time
(1) between 45 and 55 dB?
(2) between 40 and 60 dB?
(3) above 80 dB?
(b) 20% of the sound volumes will be below what value?
(c) There is a 99% chance that the sound volume will be below what value? 
If measurements are taken twice an hour during an eight hour period,
(d) what is the probability that the average volume of sound measurement for th