The number of telephone calls made daily in a certain community between 8 P.M. and 9 P.M. has a mean of 352 and standard deviation of 31. What percentage of time will there be more than 400 telephone calls made in this community between 8 P.M. to 9 P.M.?
[Given that: , where is the standard normal variate]
The number of telephone calls made daily in a certain community between 8 P.M. and 9 P.M. has a mean of 352 and standard deviation of 31. What percentage of time will there be more than 400 telephone calls made in this community between 8 P.M. to 9 P.M.?
[Given that: , where is the standard normal variate]
Solution
✅ Correct Option: 3
Standardise: . Then , i.e. about 6.06% of the time.
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