In a telephone exchange , the frequency distribution of the number of telephone calls per minute for any hour are given below :

find the average number of telephone calls.

Given below the number of telephone calls received at an exchange for 245 days:(i)Calculate the median.

In a telephone enquiry system, the number of phone calls regarding relevant enquiry follow poisson distribution with an average of five phone calls during 10-minute time intervals. The probability that there is at the most one phone call during a 10-minute time period is

In a telephone enquiry system,the number of phone calls regarding relevant enquiry follow poisson distribution with an average of five phone calls during 10 -minute time intervals. The probability that there is at the most one phone call during a 10 -minute time period is

In a telephone enquiry system, the number of phone calls regarding relevant enquiry follow poisson distribution with an average of five phone calls during 10-minute time intervals. The probability that there is at the most one phone call during a 10-minute time period is

In a telephone enquiry system, the number of phone calls regarding relevant enquiry follow poisson distribution with an average of five phone calls during 10-minute time intervals. The probability that there is at the most one phone call during a 10-minute time period is

On one page of a telephone directory, there are 150 phone numbers. The frequency distribution of their unit digits is given below One of the numbers is chosen at random from the page. What is the probability that the unit digit of the chosen number is less than 3 ?