Question

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 parts (a) and (b)
Arrivals Frequency
0 21
1 46
2 40
3 36
4 25
5 20
6 8
7 3
8 1
a. Compute the expected number of arrivals per minute.
μ=___( please type as an integer or a decimal)
b. Compute the standard deviation
σ=___(please round to three decimal places as needed)

Answer 1

Answer:

a. μ = 25

b. σ = 16.496

Step-by-step explanation:

Note: See the attached excel for the calculation of Mean and Deviation from Mean.

Let: N = Number of observation = 9

F = Frequency

Therefore, we have:

a. Compute the expected number of arrivals per minute. μ=___( please type as an integer or a decimal)

From the attached excel file, we have:

Total F = 200

Therefore, we have:

μ = Mean = Total of F / (N - 1) = 200 / (9 - 1) = 25

b. Compute the standard deviation σ=___(please round to three decimal places as needed)

From the attached excel file, we have:

Total (F -  μ)^2 = 2,177

σ = Standard deviation = (Total of (F -  μ)^2 / (N - 1))^0.5 = (2,177 / (9 - 1))^0.5 = 16.496

Download xlsx