STATISTICS FOR MANAGEMENT
EXERCISES(PROBABILITY DISTRIBUTIONS-ESTIMATION-HYPOTHESIS TESTS-REGRESSION)
1. In a screw production factory ,in a particular bench , screws having mean of 2mm are
produced. The dispersion is associated with normal distribution. We take a randomly
selected sample consisting of 30 screws from the produced population and we compute the
mean of this sample as 1.98mm and standart deviation 0.06. Verify whether this bench
works out accurately or not in a significance level of 0.05.
2. In canned food factory, it is written on the products as brut 400 gr. An observer wants to
decide about the brut weights of canned food and randomly selects 81 cans. He finds the
mean of this sample as 398 gr. And standart deviation as 12gr. In a high weight
circumstance, factory will not reach an ideal profit, in low weight circumstance customer
service would not be realized. Can we say that the factory produces can foods in a weight of
400 gr. (Significance level : 0.01)(It is known that the distribution is normal)
3. It is known that the distribution of distance a driver can drive by ‘A’ brand cars with 10 lt
benzin has a normal distribution. Randomly selected 16 cars, It is observed that the mean of
distance a driver could drive with 10 lt benzin is 90 km. And standart deviation is 6km.
a. Find the standart error of the distribution.
b. Estimate the distance a driver can drive by ‘A’ brand cars with 10lt. benzin in a
confidence level of 95%)
c. Draw the curve and show the limits on the curve.
4. The highschool nurse is interested in knowing the average height of students at the school,
but she does not have enough time to examine the records of 430 students. She randomly
selects 48 students and finds the mean of this sample 64.5 inches and standart deviation
2.3inches.
a) Find the standart error of the mean.
b) Estimate the confidence interval in a confidence level of 90%
c) Draw the curve and show the limits on the curve
5. It is assumed that annual income of families in a region is 9,000TL. From this region 100
families have been randomly selected and their annual income mean has been determined
as 8,020TL. and standart deviation as 1,400TL. Can we say that the annual income of families
in this region is 9,000 TL .(Significance Level:0.01)
STATISTICS FOR MANAGEMENT
EXERCISES(PROBABILITY DISTRIBUTIONS-ESTIMATION-HYPOTHESIS TESTS-REGRESSION)
6. Campus Stores has been selling the Believe or Not : Wonders of Statistics Study Guide for 12
semesters and would like to estimate the relationship between sales and number of sections
of elementary statistics taught in each semester.The following data have been collected.
Sales(Units)
33
38
24
61
52
45
65
Number of Sections
3
7
6
6
10
12
12
a) According to the data; Develop the estimating equation.
82
13
29
12
63
13
50
14
b) Calculate the coefficient of determination and the coefficient of correlation.
7. Zippy Cola is studying the effect of its latest advertising campaign. People chosen at
random were called and asked how many cans of Zippy Cola they had bought in the past
week and how many Zippy Cola advertisements they had either read or seen in the past
week.
Number of Ads
Cans Purchased
3
11
7
18
4
9
2
4
0
7
4
6
a) Determine dependent and independent variables.
b) Develop the estimating equation.
c) Calculate coefficient of determination and coefficient of correlation.
1
3
2
8
79
15