Reference no: EM132501839

1.Tourism Queensland monitored the duration of calls to its customer service line. Over several years, they found that the length of a phone call could be modelled as a normal distribution with a standard deviation of 1.56 minutes.

a)Find the probability that the length of a phone call of a randomly selected customer would be within two minutes of the true mean length of a phone call (correct to 3 decimal places). 

b)If 578 calls were received during a particular shift, how many phone calls would be within two minutes of the true mean length of a phone call? Use your rounded answer, with 3 decimal places, from part a. (Round your answer to the nearest whole number.)

2.The International Air transport Association survey asked business travellers about the purpose of their most recent trip. Nineteen percent responded that it was for an internal company visit. Suppose 670 business travellers are randomly selected, find the probability that between 18% and 21% of them say the reason was for an internal company visit.

3.A study measured the amount of consultation time physicians took with patients. From the study, it was determined that the consultation time was normally distributed with a mean of 15 minutes and a standard deviation of 2 minutes. Ten percent of the patients require less than how many minutes?

4.AMART has monitored the duration of calls to its customer service over a long period of time and found that length of calls could be modelled as a normal distribution with a true mean of 4.59 minutes and a variance of 1.28 minutes squared. What probability of calls last for between 3 and 7 minutes? Give your answer to 4 decimal places.