Acatalog company that receives the majority of its orders by telephone conducted a study to determine how long customers were willing to wait on hold before ordering a product. the length of waiting time was found to be a variable best approximated by an exponential distribution with a mean length of waiting time equal to 2.8 minutes (i. e. the mean number of calls answered in a minute is 1/2.8). what proportion of callers is put on hold longer than 2.8 minutes?

0.3679

Step-by-step explanation:

The cumulative distribution function for exponential distribution is :-

, where  is the mean of the distribution.

Given :  A mean length of waiting time equal minutes

i.e. Mean number of calls answered in a minute

Now, the proportion of callers is put on hold longer than 2.8 minutes is given by :_

Hence, the proportion of callers is put on hold longer than 2.8 minutes = 0.3679

answer: 20

step-by-step explanation:

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b