Download Supp_2E13_B

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
1. Find the mean of each of the following sets of data.
(a) 2, 3, 4, 5, 8, 8
(b) 20, 21, 24, 25, 28, 29, 32, 39, 40, 42
(c) 10, 15, 20, 50, 120, 150, 200, 315
2. There are 8 staff members in a company and their monthly salaries are as follows:
$4 000, $6 000, $6 500, $7 500, $7 500, $9 500, $10 500, $20 000
Find the mean of their monthly salaries.
3. The high jump records of 6 boys are as follows:
172 cm, 170 cm, 163 cm, 176 cm, 165 cm, 183 cm
Find the mean of the high jump records.
4. If 7 glasses are sold at $294 in total, find the mean selling price of the glasses.
5. The total weight of 100 oranges in a carton is 12.5 kg. What is the mean weight of the oranges? (Express
your answer in g.)
6. There are 6 people having dinner in a restaurant, and each of them needs to pay $122.5 on average. How
much do they pay in total?
7. If the mean time required for Kent to answer a multiple choice question is 2.5 minutes, how long does
he take to answer 30 multiple choice questions?
8. If the mean of 2, 5, x, 2x, 3x  1 and 12 is 6, find the value of x.
9. There are 5 players in a basketball team. The heights of 4 of them are 180 cm, 182 cm, 184 cm and
190 cm. If the mean of the heights of the 5 players is 185 cm, find the height of the 5th player.
13.7
 2009 Chung Tai Educational Press. All rights reserved.
10. Candy bought three gifts at a mean price of $95. If she buys one more gift at $102, what is the mean
price of these four gifts?
11. The mean time for an athlete to complete 5 times of 400 m was 54.16 s. If the athlete took 55.2 s to
complete the 6th time of 400 m, what would be the mean time for the athlete to complete 6 times of
400 m? (Give your answer correct to 2 decimal places.)
12. The mean score of 5 tests of Peggy is 45.5. If there is one more test for her and she wishes t o obtain a
mean score of 50 for the 6 tests, what score should she get in the 6th test?
13. (a) Complete the following frequency distribution table.
Datum x
Frequency f
fx
13
3
39
14
7
15
9
16
1
Total
(b) Find the mean of the data in (a).
14. The mean of two numbers is 10 and the mean of another three numbers is 15.
(a) Find the sum of these five numbers.
(b) Hence find the mean of these five numbers.
15. In November, Micky obtained a mean score of 24.5 in 6 basketball games. In Decem ber, he obtained
a mean score of 21 in 8 basketball games. Find the mean score obtained by Micky in each game from
November to December.
16. (a) Complete the following frequency distribution table.
Class interval
Class mark x
Frequency f
26 - 30
3
31 - 35
9
36 - 40
15
41 - 45
8
46 - 50
5
Total
(b) Find the mean of the data in (a).
13.8
 2009 Chung Tai Educational Press. All rights reserved.
fx
17. The following frequency distribution table shows the time spent by a group of people in watching TV
last week.
Time (hour)
Class mark x (hour)
Frequency f
16 - 20
15
21 - 25
25
26 - 30
30
31 - 35
20
36 - 40
10
fx (hour)
Total
(a) Complete the table.
(b) Find the mean time spent by the group of people in watching TV last week.
18. The weights of the students in S2A are as follows:
Weight (kg)
30 - 34
35 - 39
40 - 44
45 - 49
50 - 54
Frequency
8
12
12
x
2
If their mean weight is 39.75 kg, find the value of x.
19. It is known that the mean of the number of push-ups done by S2A boys in a minute is 21; that done by
the S2A girls is 9; and that done by the whole class is 13.4. If there are 30 students in S2A, find the
number of boys and the number of girls in the class.
20. The following frequency polygon shows the time required by S2A students for completing the
homework last night. It is given that the first class interval is 31 minutes - 40 minutes. Find the mean
time for them to complete the homework.
Frequency
The time required by S2A students to complete the homework last night
15
10
5
0
25.5
35.5
45.5
55.5
65.5
75.5
85.5
Time (min)
13.9
 2009 Chung Tai Educational Press. All rights reserved.
21. The scores of Cindy in the first five dictations were 65, 72, 72, 80 and 90. Given that the full score of
each dictation is 100, can Cindy get a mean score over 80 in the first six dictations? Explain briefly.
22. The following shows the prices of mobile phones from two brands, Nobia and Sorry Edison.
Nobia
$480
$980
$1 480
$1 780
$2 680
$3 280
$4 380
$5 680
Sorry Edison
$399
$699
$1 099
$1 299
$1 699
$2 499
$3 099
$3 699
$4 499
$5 999
(a) Find the mean price of mobile phones for each brand.
(b) By considering the means, which brand set a lower selling price in general?
23. Find the median of each of the following sets of data.
(a) 3, 4, 6, 8, 10
(b) 2, 7, 8, 9, 12, 15, 18, 19, 21
(c) 15, 18, 21, 29, 32, 35, 40, 47, 52, 60, 100, 108
24. Find the median of each of the following sets of data.
(a) 8, 2, 5, 9, 1, 7, 4
(b) 13, 17, 12, 10, 18, 21, 16, 20, 24, 13
(c) 2.3, 8.2, 4.1, 3.0, 2.9, 1.8, 0.8, 1.4, 0.9
25. The respective weights of ten pumpkins are 5.4 kg, 6.5 kg, 4.8 kg, 7.2 kg, 8.0 kg, 6.8 kg, 7.5 kg, 7.2 kg,
8.4 kg and 7.0 kg. Find the median weight of these ten pumpkins.
13.10
 2009 Chung Tai Educational Press. All rights reserved.
26. The following frequency distribution table shows the pocket money of 49 primary students in a day.
Find the median pocket money of these students.
Pocket money ($)
3
4
5
6
7
8
9
10 or more
Frequency
2
5
10
12
4
8
5
3
27. The following stem-and-leaf diagram shows the Mathematics test scores of the students in S2A.
Mathematics test scores of the students in S2A
Stem (10 marks)
Leaf (1 mark)
4
4 6 6 6
5
0 1 1 3 8 9
6
7
8
2 4 7 7 7 8 8 9 9
1 1 2 3 3 3 5 5 7 8 9
2 8
(a) How many students are recorded in the above stem-and-leaf diagram?
(b) Find the median test score.
28. The cumulative frequency polygon shows the intelligence quotient (I.Q.) test results of 100 students.
Find the median I.Q. test result of the students.
I.Q. test results of 100 students
100
90
Cumulative frequency
80
70
60
50
40
30
20
10
0
40.5 50.5 60.5 70.5 80.5 90.5 100.5
Score
13.11
 2009 Chung Tai Educational Press. All rights reserved.
29. The following cumulative frequency table shows the duration (in second) for holding breath among
50 students.
Holding breath for less than (s)
Cumulative frequency
10
9
20
29
30
40
40
47
50
49
60
50
(a) According to the above table, construct a cumulative frequency polygon.
(b) Hence find the median duration for holding breath among these 50 students.
30. Find the median of x + 1, x + 3, x + 5, x + 1 and x + 2.
31. The median of a set of data 10, 12, 14, 15, x, x + 5, 24, 25, 28 and 31 arranged in ascending order is
20.5. Find the value of x.
32. The following frequency distribution table shows the number of movies watched by 50 people during
a summer vacation.
Number of movies watched
0
1
2
3
4
5 or more
Frequency
4
8
13
y
8
3
(a) Find y.
(b) Find the median number of movies watched.
33. It is known that the sales volume (in glasses) of soya milk in the past six days were 121, 103, 106, 110,
106 and 113.
(a) Find the median sales volume of soya milk in the past six days.
(b) If 135 glasses of soya milk were sold today, find the median sales volume of soya milk in these
seven days.
13.12
 2009 Chung Tai Educational Press. All rights reserved.
34. The following are quotations for the removal service received by Mr. Chan from ten removal
companies.
$800, $1 000, $1 300, $1 400, $1 250, $1 300, $1 200, $1 200, $1 500, $1 100
(a) Find the median quotation.
(b) If the quotation of $1 800 is written as $800 by mistake, what is the actual median quotation?
35. The respective amounts spent by Mrs. Chan on five purchases at a supermarket are $54, $82, $125,
$163 and $x. It is given that the mean amount spent on these five purchases is $103.
(a) (i) Find the value of x.
(ii) Find the median amount spent on these five purchases.
(b) If Mrs. Chan spent $102 on the sixth purchase at the supermarket, find the median amount spent on
these six purchases.
36. The following back-to-back stem-and-leaf diagram shows the weights of 30 chickens from each farm.
The weights of 30 chickens from each farm
Farm A
Leaf (0.1 kg)
Stem (1 kg)
Farm B
Leaf (0.1 kg)
8 4 4
1
2 2 3 5 6 7 9
9 9 6 3 3 1 0
2
1 1 1 2 2 4 5 5 6 8 9
8 8 7 6 5 5 4 4 4 2 1 0
3
0 0 1 1 1 4 4 6 7 8
7 7 6 5 3 2 2 1
4
0 2
(a) Find the median weight of chickens from farm A.
(b) Find the median weight of chickens from farm B.
(c) (i) Draw a stem-and-leaf diagram to show the distribution of the weights of a total of 60 chickens
from farms A and B.
(ii) Hence find the median weight of these 60 chickens from farms A and B.
37. It is given that x is a positive integer. If the median of 10, 13, 15, x and x + 2 is 14, find all the
possible values of x.
13.13
 2009 Chung Tai Educational Press. All rights reserved.
38. The following cumulative frequency curves show the prices of flats in two districts.
The prices of flats in two districts
50
Cumulative frequency
40
District A
30
20
District B
10
0
2
3
4
5
6
7
Price (thousand dollars / square foot)
(a) Find the median of the prices of flats in each district.
(b) According to the result of (a), which district has a higher flat price in general?
39. Find the mode of each of the following sets of data.
(a) 10, 10, 10, 10, 12, 15, 15, 18, 20
(b) 7, 7, 8, 8, 9, 9, 9, 10, 10, 12, 12
(c) 20, 21, 21, 25, 26, 26, 28
40. Find the mode of each of the following sets of data.
(a) 3, 6, 8, 4, 3, 6, 8, 5, 3
(b) 8, 5, 13, 0, 5, 9, 13, 5
(c) 1.7, 2.3, 1.6, 1.7, 2.0, 2.3, 2.1, 1.9
13.14
 2009 Chung Tai Educational Press. All rights reserved.
41. Find the modal class of each of the following sets of data.
(a)
(b)
Class interval
26 - 30
31 - 35
36 - 40
41 - 45
46 - 50
Frequency
3
10
14
6
5
Class interval
1-3
4-6
7-9
10 - 12
13 - 15
16 - 18
Frequency
2
9
19
14
19
14
42. Find the mode of x, x  1, x  3, x, x  1, x  1 and x.
43. The following table shows the number of children in 1 000 families. Find the mode of the number of
children in these 1 000 families.
Number of children
0
1
2
3
4
5 or above
Frequency
204
347
234
159
50
6
44. The following bar chart shows the sales volume of five types of fruit juice. Find the mode of the sales
volume of fruit juice.
The sales volume of five types of fruit juice
50
45
Sales volume (L)
40
35
30
25
20
15
10
5
0
Mango
juice
Apple
juice
Papaya
juice
Orange
juice
Watermelon
juice
Fruit juice
13.15
 2009 Chung Tai Educational Press. All rights reserved.
45. The following pie chart shows the sales of four types of umbrellas of a company in a year. Find the
mode of the types of umbrellas sold.
Sales of four types of umbrellas in a year
Straight
106
Beach 50
Folding
42
Kid’s
46. The following stem-and-leaf diagram shows the sales volume of vacuum cleaners achieved by a
salesperson in the past 10 days. Find the mode of the sales volume.
Sales volume of vacuum cleaners
Stem (10)
Leaf (1)
0
3 3 4 4 4 7 8
1
0 2
2
0
47. The following frequency polygon shows the duration of 26 movies. The first class interval is
80 min - 89 min. Find the modal class of the duration of the movies.
The duration of 26 movies
10
9
8
Frequency
7
6
5
4
3
2
1
0
74.5
84.5
94.5
104.5
Time (min)
13.16
 2009 Chung Tai Educational Press. All rights reserved.
114.5
124.5
134.5
48. The following stem-and-leaf diagram shows the age distribution of 50 drivers when they obta ined
driving licenses of private car.
Ages of 50 drivers obtaining driving licenses of private car
Stem (10)
Leaf (1)
1
8 8 9 9
2
0 0 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 5 5 6 6 6 7 7 7 8 9
3
0 0 0 1 1 2 3 3 4 5 6 8
4
0 0 2 3 5 7
(a) Find the mode of the ages.
(b) (i) According to the above stem-and-leaf diagram, complete the following table.
Age
Frequency
18 - 22
23 - 27
28 - 32
33 - 37
38 - 42
43 - 47
(ii) Find the modal class of ages.
49. The following cumulative frequency table shows the floor area of the flats of 30 families.
2
Floor area less than (m )
Cumulative frequency
9.5
0
29.5
3
49.5
5
69.5
25
89.5
30
13.17
 2009 Chung Tai Educational Press. All rights reserved.
(a) Given that the first class interval is 10 m 2 - 29 m 2 , complete the following table.
2
Frequency
Floor area (m )
10 - 29
30 - 49
50 - 69
70 - 89
(b) Find the modal class of floor area.
50. The following frequency distribution table shows the ages of 200 students in a Japanese language
school where x and y are positive integers.
Age
16 - 20
21 - 25
26 - 30
31 - 35
36 - 40
41 - 45
Frequency
30
42
40  x
34
y
19
(a) Can the modal class be 36 - 40? Explain briefly.
(b) If the modal class is 26 - 30, write down two sets of possible values of x and y.
51. Write down a set of 8 numbers such that their mean, median and mode are 8, 7 and 6 respectively.
52. Write down a set of 5 numbers where mode > median > mean.
13.18
 2009 Chung Tai Educational Press. All rights reserved.
Related documents