Business statistics

Business Statistics

Date: 26/04/2020

Q1. Government of Saudi Arabia claims that in Buraidah, the average yearly consumption of milk per person is 35.5 gallons. A random set of researchers from Q University was appointed to test the validity of this claim. The researchers tested 120 people and found that their average yearly consumption of milk is 32.8 gallons. The standard deviation of the population is 15 gallons.

Verify the claim using the seven steps of hypothesis testing. Let α = 0.05 (5%). = 1.96 (4 Marks)

Q2. Briefly explain the following terms with the help of some examples?

(a) Normal Distribution (2 Marks)

(b) Difference between regression and Correlation? (2marks)

Q2. Albaik wanted to test their claim regarding who can eat more pieces of Chicken in a college fest at Qassim University. For the purpose, they randomly selected 22 males and 29 females. The average number of pieces eaten by males were 350 with a standard deviation of 22 (from historical data) and the average number of pieces eaten by females were 400 with a standard deviation of 18. On the basis of the samples taken for the study, estimate the difference in population means taking 5% as the level of significance and help claim that females eat more pieces of chicken than males. Alpha is 5% (Tabulated Value =1.68). (4 Marks)

Q4. Almarai Foods Ltd is a leading manufacturer of dairy products in the kingdom of Saudi Arabia. The company has launched a new brand in the four cities;Jeddah, Riyadh, Makkah and Medina. After one month, the company realizes that there is a difference in the retail price per pack of cheese across cities. Before the launch, the company had promised its employees and newly-appointed retailers that the cheese would be sold at a uniform price in the country. The difference in price can tarnish the image of the company. In order to make a quick inference, the company collected data about the price from six randomly selected stores across the four cities.

A confidence interval of 95% of taken by the researchers. The company has analyzed the data using SPSS and the output is presented in the tables below. Analyze the SPSS output and suggest whether there is a difference in the prices across the four cities in KSA? (4Marks)

ANOVA
Price
	Sum of Squares	df	Mean Square	F	Sig.
Between Groups	49.708	3	12.903	56.34	.09
Within Groups	7.250	20	.463
Total	58.958	23

Q5. ABC Corporation has witnessed a surge in the resignations across departments. Many good employees are leaving the organizations. Employees believe that this sudden surge in resignations can be attributed to the lack of work life balance. Therefore, the company has recently conducted a survey to determine the impact of working hours, job stress and job characteristics on the work life balance. The data was analysed by the SPSS and the results are presented in the table below. You are supposed to evaluate the impact of three independent variables (working hours, job stress and job characteristics) on the work life balance? (4Marks)

Model Summary
Model	R	R Square	Adjusted R Square	Std. Error of the Estimate
1	.713a	.509	.503	.82670
a. Predictors: (Constant), Working Hours, Job stress, Job characteristics

ANOVAa
Model	Sum of Squares	df	Mean Square	F	Sig.
1	Regression	171.905	3	57.302	83.843	.000b
	Residual	166.076	243	.683
	Total	337.981	246
a. Dependent Variable: Work Life Balance
b. Predictors: (Constant), Working Hours, Job stress, Job characteristics

Coefficientsa
Model	Unstandardized Coefficients	Standardized Coefficients	t	Sig.	95.0% Confidence Interval for B
	B	Std. Error	Beta			Lower Bound	Upper Bound
1	(Constant)	.326	.301		1.082	.280	-.267	.920
	Working Hours	.428	.072	.362	5.959	.000	.287	.570
	Job Stress	.140	.085	.121	1.651	.100	-.027	.308
	Job characteristics	.390	.081	.329	4.837	.000	.231	.549
a. Dependent Variable: Working Hours