1 The general manager of a store wants to know the average t

1. The general manager of a store, wants to know the average (typical) amount of time it takes for a customer to check out of his grocery store. Last Saturday between the hours of 8 am and noon the manager, along with a team of helpers, measured the amount of time it took the first 200 customers to check out at each of its open registers. The helpers recorded the time (in minutes) using a stop watch, starting when a customer first arrived at a line and ending when they had paid and received their receipt. The average time for the sample was 6.5 minutes.

Answer each of the following questions pertaining to the above paragraph. (40 points)

a) Identify the population being targeted by this study.

b) Identify the sample.

c) Can we say the sample chosen was randomly selected? If it is, explain why. If it\'s not, explain why not and note what type of sample it could be (given the information above).

d) Identify the variable?

e) Is the data that resulted from this variable QUALITATIVE or QUANTITATIVE? If you say quantitative, further classify the variable as discrete or continuous.

f) Identify the statistic.

g) What is the parameter we are trying to estimate?

h) What\'s your best estimate for the value of the parameter? Explain how accurate this estimate is.

Solution

1) The population under study must be the customers visiting the grocey store on 7 days of week

2) The sample is the customers who entered the store and left it form 8am to noon.

3) It may not be a random sample as out of 7 days only saturday was studied purposefully. So, we can term it a purposive sample.

4) The variable under study is the time taken by the customers to leave the store.

5) The data is essentially quantitative and continuous. Since time is measured is a continuous scale and it gives quantities such as 0,1.4 etc etc.

6) The statistic is the sample average.

7) The parameter under study is the population average.

8) The best estimate here according to given info is the 6.5 minitues which is sample average. It is fairly accurate since sample mean is always unbiased estimator of population mean,