5) a) It is conjectured that an impurity exists in 30% of all drinking wells in a certain rural community. To gain some
Posted: Sun Jul 10, 2022 11:46 am
5) a) It is conjectured that an impurity exists in 30% of alldrinking wells in a certain rural community. To gain some insightinto the true extent of the problem. It is determined that sometesting is necessary. It is too expensive to test all the wells inthe area. So, 10 are randomly selected for testing. What is theprobability that more than 3 wells are impure?
b) Phone calls arrive at the rate of 48 per hour at thereservation test for ABC Airways.
I. Suppose no calls are currently on hold. If the agent takesfive minutes to complete the current call. How many callers do youexpect to be waiting that time?
II. What is the probability that 3 calls will be waiting?
c) I. Draught excluder for doors and windows is sold in rolls ofnominal length 10 meters. The actual length X meters of draughtexcluder on a roll may be modeled by a normal distribution withmean 10.2 and standard deviation is 0.15. Determine the 𝑃(10 < 𝑋< 10.5)
II. The height of 2000 students are normally distributed with amean of 174.5cm and a standard deviation of 6.9cm. Assuming thatthe heights are recorded to the nearest half – centimeter. How manyof these students would you expect to have height less than160cm?
d) Note that the normal distribution for a plot yield the mean660Kg and the standard deviation is 32Kg. What is the minimum yieldthat can be obtained from the best 100 plots in a category of 1000plots
b) Phone calls arrive at the rate of 48 per hour at thereservation test for ABC Airways.
I. Suppose no calls are currently on hold. If the agent takesfive minutes to complete the current call. How many callers do youexpect to be waiting that time?
II. What is the probability that 3 calls will be waiting?
c) I. Draught excluder for doors and windows is sold in rolls ofnominal length 10 meters. The actual length X meters of draughtexcluder on a roll may be modeled by a normal distribution withmean 10.2 and standard deviation is 0.15. Determine the 𝑃(10 < 𝑋< 10.5)
II. The height of 2000 students are normally distributed with amean of 174.5cm and a standard deviation of 6.9cm. Assuming thatthe heights are recorded to the nearest half – centimeter. How manyof these students would you expect to have height less than160cm?
d) Note that the normal distribution for a plot yield the mean660Kg and the standard deviation is 32Kg. What is the minimum yieldthat can be obtained from the best 100 plots in a category of 1000plots