data distribution

1) 25 POINTS
Considering following data distribution:

0,4,4,5,5,5,6,6,6,6,7,7,8,9

a) Calculate mean, median, and quartiles

b) Draw the boxplot

c) Is there any outlier? Why?

2) 25 POINTS
The scores of adults on a IQ test are approximately normal with mean 100 and standard deviation 15.

a. What proportion of adults have an IQ below 90?

b. What proportion of adults have an IQ above 120?

c. What proportion of adults have IQ between 90 mm and 110 mm?

3) 25 POINTS
It has been found that that the average final grade of a Group of 50 Statistic students at the EU has been 82 points. Suppose the study follows a normal distribution with standard deviation 4.

a) Estimate the mean of all statistic students as the EU in using 95% confidence interval. (show all the calculations)

b) Write the conclusion of your result

4) 25 POINTS
A regression analysis has been conducted between the annual income (in 1000 euros) and the work experience (in years) of Managing Director s in Barcelona area The results are summarized below.

a) Define the independent and dependent variables. What can you say about the correlation between them.

b) Find R and R2 and interpret Write the regression model and interpret the coefficients.

c) Estimate the average annual income of a Manager who has 10 years of work experience.

 

years

 

1

 

1

 

2

 

4

 

5

 

6,5

 

8

 

10

 

15

 

income

 

60

 

68

 

72

 

77

 

83

 

88

 

90

 

93

 

100