A multinational bank issuing Master Card is monitoring the use of credit card account holders in the context of their spending habits. A market survey shows that the average monthly spending of its...

A multinational bank issuing Master Card is
monitoring the use of credit card account holders
in the context of their spending habits. A market
survey shows that the average monthly spending
of its regular card users is normally distributed
with mean Rs. 2800 and standard deviation Rs.
900. The customer is classified into four
categories according to pattern of spending:
i. Category 1 spends less than Rs. 2000
ii. Category 2 spends Rs. 2000 or more but less
than Rs. 3000
iii. Category 3 spends Rs. 3000 or more but less
than Rs. 4000
iv. Category 4 spends Rs. 4000 or more
What proportion of customers would you expect
to fall into each category?