Bài tập thống kê trong kinh doanh – xác xuất thống kê eng

Draw the appropriate graph BoxPlot boxbot box to assess the symmetry of the data of the two methods mentioned above:...7 b.. From the data obtained, by using regression analysis... Pleas

BÀI TẬP THỐNG KÊ TRONG KINH DOANH – XÁC XUẤT THỐNG

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Exercise 1

1 Graphing appropriate to assess the symmetry of the two methods above

2 Statistical characteristics for two methods

3 Find the 95% confidence interval for the average strength of the tire in each method

4 Conducted testing to compare the average strength of the tires of the two methods above and conclude with α = 0.05

Exercise 2

a Plotting the point spread to comment on the relationship possible between X and Y

b Please estimate the relationship Simple linear regression filings and market quality products Conclusion?

c Testing the relationship exists a linear correlation between the Y and X

d Said coefficient R2 and explain its meaning

e Please share if forecasts scale for product quality is 40, 50, 80 and 90

f According to you, whether only used as one variable X on Y has to explain enough If you can put more independent variables may be other factors?

TABLE OF CONTENT

TABLE OF CONTENT 2

INTRODUCTION 4

RESEARCH OF CONTENT 5

Part 1 Theoretical basics 5

1 The core of management's decision making (decisions) 5

2 The components of decision making 5

Part 2: Exercise 7

Exercise 1 7

a Draw the appropriate graph (BoxPlot) boxbot box to assess the symmetry of the data of the two methods mentioned above: 7

b As of the statistical characteristic of two methods and compare 7

c Find the confidence interval 95% for the average strength of the tire in each method, see the average oscillation is 8

d Please conduct testing to compare the average strength of tires in the 2 methods and conclude with α = 0:05 8

e Make checks pair with α = 0.05 (assuming the data was obtained) 9

Exercise 2 10

a Graphing scattered points to comment on the relationship possible between Y and X 10

b From the data obtained, by using regression analysis

d From the results of the regression analysis above we have R2 = 0896 This means that the change in market share Y is explained by 89.6% due to the variation in the quality of the product X 12

e Please share if forecasts scale for product quality is 40,50,80,90: regression analysis of the data of the two parameters Y and market share product quality X by megastat forecast market share in the case of 40 quality indicators,

50, 80 and 90 have been following results: 12

f According to you, is used as a variable X on Y has to explain enough If you can put more independent variables may be other factors? 13

LIST OF REFERENCES 14

The era we live in the "age of information", and for now, "the full utilization of information assets is a critical success factor, and now that has the ability to exploit maximum understanding will have a big advantage in the global business world

"However, this scenario is still far away for enterprises in Vietnam, where the overwhelming information on the transmission medium, but the lack of tools to process information correctly

The volume of data a company receives daily is huge because they come from

so many parts of the company That's not to mention the external data transmission system Some enterprises do not have a clear approach to system data into meaningful information and develop performance indicators (KPIs) from such information To obtain useful information for making management decisions, businesses need to go through four steps: collecting raw data, raw data classification, data analysis and screening information However, the first step is where most people were trapped How we can get accurate information and practical right time to make management decisions when initial data collection was spending too much time like that? This has slowed the decision making process, and thereby become a huge disadvantage to prevent the development of enterprises

Every business needs to have accurate decisions to shape the future direction, and since then, development The only way to improve the quality of decisions is to improve information systems before, to provide practical information, consistency and application to decision makers In the next article, we will discuss more about the solution eliminates the three obstacles mentioned above, helps enterprises take the decision making to successful governance

RESEARCH OF CONTENT

Part 1 Theoretical basics

1 The core of management's decision making (decisions).

The decision of the management, including: planning, choice of action plans, establishing organizational structure, division of responsibilities and powers, to compare the actual situation with the plan, the choice of test method investigation, take care of the present plan, organize and control for all levels of management and all aspects of the management process Decision of almost synonymous with management

The management decisions are divided into two major groups: Decision overarching values are decisions on the final goal; decisions the fact that decisions relating to the implementation of the target (actual evaluation) The combination 2 kinds of decisions that are considered to be the focus of management A management decision can only be considered valid if the element contains practical and feasible It was decisions "reasonable - objectivity" not decisions "reasonable - subjective" (optimal perfect)

2 The components of decision making

Decisions are made up of over four stages linked together: to collect and analyze information economy - society; design action plans to choose from; Choosing

a viable option; verification assessment schemes have chosen to supplement perfect All activities within an organization can be divided into two categories with two kinds

of decisions: activities took place many times require sequential decisions, and activities taking place for the first time need not follow policy decisions sequence It should try to raise the level of decision-making process to improve the control system effectively, while enhancing the air conditioning system, coordination of the organization Decisions of non-creative process, without precedent, but based on the knowledge and methods available to process, including the use of experience The division two types of decisions is relative

Through a target system - the means to unify operations It is a combination of human and machine (electronic) to decision makers; can overcome the lack of

knowledge and information in a communication network according to the two-dimensional channels

Choosing the right training methods or decentralization in decision-making powers to the authorities and clear Thanks to the automated determination of the order, the handling of issues related with the right training methods to be reasonable,

to reduce the interference of intermediate to work at grassroots level However, that method can not be used in any situation; have to think about stimulus, making decisions can mobilize people trying to do Organizational forms in the future is still the hierarchy consists of three levels: level of production and distribution, supply dominate decision making in sequence, control level during operation of the facility Need decentralized decision making, creating "the reasonable approval" for the autonomy of their subordinates

The decisions taken with science, such decisions must be based on a plan The plan must set out the goals to be achieved The objective of the political society, there iêu item of business at the forefront it is profitable

Measure, calculate profit or value of the different actions, we get the result or accounting In the calculation must take into account its revenues will be compared with the cost of removal Costs can be effective or ineffective

Part 2: Exercise

Exercise 1

a Draw the appropriate graph (BoxPlot) boxbot box to assess the symmetry of the data of the two methods mentioned above:

Through the data, to assess the symmetry of the data of the two methods above Can use the following graph:

a.

Graph 1: Boxplot by the method 1

Graph 1: Boxplot by the method 2 Reviews:

Then look at the two graphs on the data we see method 1 is relatively symmetrical because due to the length of the equivalent box Method 2 misses to the left

b As of the statistical characteristic of two methods and compare

3rd quartile 2,774.50 2,757.75

Commented: We saw both methods are 40 observations The average value equivalent (2742 & 2729) Comparing the median well worth the equivalent

Comparison of dispersion method 2 has a larger dispersion by the standard deviation and interquartile range are greater than method 1

Both methods are no outliers

c Find the confidence interval 95% for the average strength of the tire in each method, see the average oscillation is.

Conclusion: With the reliability 95% of the average strength for method 1 was from 2,732 to 2,753 As for method 2 is 2,717 to 2,741

d Please conduct testing to compare the average strength of tires in the 2 methods and conclude with α = 0:05

We have; Ho ; ℳ1 = ℳ2 In which ℳ1 : Strength of tires in Method 1

H1 ; ℳ1# ℳ2 ℳ2 : Strength of tires in Method 1

Hypothesis Test: Independent Groups (t-test, pooled variance)

78 Df 13.225 difference (PP1 – PP2) 1,278.139 pooled variance

35.751 pooled std dev

7.994 standard error of difference

0 hypothesized difference

1.65 T 1021 p-value (two-tailed) Conclusion:

P-value = 0.1021 is greater than α = 0.05 should not reject H0

It is concluded tire endurance average of the two methods are the same (as the person in question number two)

e Make checks pair with α = 0.05 (assuming the data was obtained).

Then, we saw a few broken tire on the road During the investigation, on the assumption was made A record sheet for the test was conducted with 40 pairs of randomly selected samples other Each tires in pairs are produced according to two different methods (in phase with the improvement of methods), while all other stages

in the production process is the same It is suggested that the test is more appropriate pair

If this is considered experimental in pairs, we use the data pairs in which each pair of Method 1 and Methed 2 included Using software datasets pair

Hypothesis Test: Paired Observations

0.000 hypothesized value 2,742.575 mean PP1

2,729.350 mean PP2 13.225 mean difference (PP1 - PP2) 48.480 std dev

7.665 std error

40 n

39 df

1.73 t 0924 p-value (two-tailed)

With a p-value = 0.0924 is greater than α = 5% should also not rejected H0 So

if using pairs of data, the average strength of 02 tires method is considered to be the same

Exercise 2

a Graphing scattered points to comment on the relationship possible between Y and X

CHART POINT SPREAD MARKET SHARE IN QUALITY

b From the data obtained, by using regression analysis MegaStat/Correlation Regression/Regression Analysis of two parameters share of Y and the quality of the product X have the following results:

Regression analysis was used to predict the value of the dependent variable based on the value of at least one independent variable Explain the impact of the change in the independent variable on the dependent variable The relationship between the two variables Y and X are described by a linear function

Regression Analysis

ANOVA table

variables coefficients std error t (df=15) p-value 95% lower

95% upper

So, the two regression parameters are written as follows

Y = β0 + β1X = -2.7054 + 0.1784X

Blocking coefficient β0= -2.7054

The slope β1 = 0.1784

Conclusion: Do β1> 0 so Y and X variables in the same direction so as quality improves, the market share will increase If quality changes one point they changed 0.1784% market share

c To test the linear correlation between market share and product quality or not, it is assumed that there is no correlation with (β1 = 0) and we test the hypothesis pair follows:

H0: β1 = 0 There is no linear relationship

H1: β1 # 0 There is a linear relationship

From the results of the regression analysis above we see p value = 9.30E-09-<α

= 0.05 Such a basis to reject H0 means that there is a linear relationship between market share and product quality

Conclusion: Between X and Y there exists correlation relationship strictly

linear

d From the results of the regression analysis above we have R2 = 0896 This means that the change in market share Y is explained by 89.6% due to the variation in the quality of the product X

Linear regression models overall application as follows:

And given the coefficient of determination r2:

Therein:

A: The linear relationship of the dependent variable

B: The random error of the dependent variable (or noise)

Determination of r2 values in the range 0 ≤ r2 ≤ 1

Thus the meaning of r2 is:

- r2 greater, the linear relationship of two variables Y and X more closely If r2 =

1, the relationship between two variables is a perfect linear relationship

Yi = β0 + β1Xi + εi

A

A + B

r2 =

Regression Analysis

ANOVA table

variables coefficients std error

t (df=15) p-value

95%

lower

95% upper

Predicted values for: Y

95% Confidence Intervals 95% Prediction Intervals

X Predicted lower upper lower upper Leverage

From the above results we can predict the market outcome Y corresponding to the given level of quality according to the following table:

X

40

Y are forecast(%)

4.431

So the product's market share is forecast at 4,43% to the quality scale is 40; 6,215% gain market share with 50 quality scale

f According to you, is used as a variable X on Y has to explain enough If you can put more independent variables may be other factors?

If we only used as a variable X on Y to explain the fact that not enough market share of the independent variable Y depends quality product X is 89.6% There's also a number of other independent variables Y impact on factors such as pricing, marketing costs, management costs,etc,

LIST OF REFERENCES

1) Lecture Course Management Decision-making, Dr Nguyen Manh The, 2014

2) International Business Administration, Ngo Thi Tuyet Mai, 2014

3) Business Administration, Nguyen Thu Huong, 2013

4) Protection of domestic production, Phan Van Cuong, 2013

5) Mining investment efficiency, Luu Nhat Ha, 2013

6) Corporate Governance Handbook, Le Minh Phong, 2013