In: Statistics and Probability
The number of arrivals per minute at a bank located in the central business district of a large city was recorded over a period of 200 minutes, with the results shown in the table below. Complete (a) through (c) to the right.
Arrivals, Frequency
0 13
1 25
2 47
3 40
4 32
5 23
6 12
7 6
8 2
Compute the standard deviation.
What is the probability that there will be fewer than 2 arrivals in a given minute?
Relative Frequency gives the answer of probability part. Relative frequency is nothing but ratio of frequency of a class and total frequency (here total frequency is 200).
Let x denotes number of arrivals and f denotes the frequencies.
where, n is total frequency (200) i.e.
Sample Standard deviation :
(Answer)
■ Probability that there will be fewer than 2 arrivals in a given minute = Probability that there will be 0 arrivals in a given minute + Probability that there will be 1 arrivals in a given minute = 0.065 + 0.125 = 0.19 (Answer)