Elementary Statistics



Elementary Statistics

Question 1

The number of cars sold per month by a car dealer in 36 months are recorded as follows:

25

20

15

20

17

27

30

15

18

31

35

22

15

16

45

41

25

23

38

18

20

23

36

38

42

40

16

33

35

22

24

25

30

36

41

18

Construct a cumulative frequency distribution for the above data.

Number of Cars Sold Per Month

Frequency

Percent

Valid Percent

Cumulative Percent

Valid

15

3

8.3

8.3

8.3

16

2

5.6

5.6

13.9

17

1

2.8

2.8

16.7

18

3

8.3

8.3

25.0

20

3

8.3

8.3

33.3

22

2

5.6

5.6

38.9

23

2

5.6

5.6

44.4

24

1

2.8

2.8

47.2

25

3

8.3

8.3

55.6

27

1

2.8

2.8

58.3

30

2

5.6

5.6

63.9

31

1

2.8

2.8

66.7

33

1

2.8

2.8

69.4

35

2

5.6

5.6

75.0

36

2

5.6

5.6

80.6

38

2

5.6

5.6

86.1

40

1

2.8

2.8

88.9

41

2

5.6

5.6

94.4

42

1

2.8

2.8

97.2

45

1

2.8

2.8

100.0

Total

36

100.0

100.0

Draw a cumulative frequency polygon of the type “less than or equal to”.

From the cumulative frequency polygon, how many months does the dealer sell less than 20 cars?

From the cumulative frequency polygon, with the type less than or equal, there are 12 months in which the dealer sold less than 20 cars.

Calculate the percentage of months with more than 30 cars sold.

There are 13 months ...