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Statistics - Mean

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Question 1


To calculate the mean, add up all the numbers, and divide by how many there are.
Find the mean of the following (non calculator):

a) $2,3,7$  a s v d
b) $1,4,7,8$  a s v d
c) $4,8,11,12,15$  a s v d
d) $8,2,6,8$  a s v d
e) $11,2,14,5$  a s v d
f) $2,3,4,5,6$  a s v d
g) $9,5,7,3,6,8,4$  a s v d
h) $8,12,4,17,4$  a s v d
i) $18,1,17,14,6,2$  a s v d
j) $101,102,105,108$  a s v d
k) $5,6$  a s v d
l) $7,9,9,4$  a s v d
m) $13,2,7,18,3$  a s v d
n) $18,97,14,11$  a s v d
o) $64,14,43,11,72$  a s v d


Question 2


Find the mean of the following (calculator):

a) $14,17,22,44$  a s v d
b) $35,5,36,22,15$  a s v d
c) $47,12,94,24,1,56$  a s v d
d) $3,3,3,3,3,5,5,5,5,5$  a s v d
e) $131,166,131,155,201,59$  a s v d
f) $22.4,55.9,18.5,24.3$  a s v d
g) $101.4,55.8,23.7,187.3,11.2,400$  a s v d
h) $323.9,523.11,53.4,911.54,75.5,322.74,632.55,233.76$  a s v d

i) $3146,414,5317,1432,8794,1342,5237,2381,1235,548,587,4892$  a s v d



Question 3


Answer the following worded questions:

a) I ate the following servings of fruit in a week:
  $3,4,3,5,2,0,4$
What was the mean amount of fruit I ate each day?  a s v d

b) Over a season I scored the following in matches:
  $4,7,2,4,6,2,5,2$
What is my mean score?  a s v d

c) What is the mean of the following prices?
  $\$2.50,\$4.25,\$3.75,\$8,\$1.50$
 a s v d

d) Sam has $10$ friends at his birthday. Their ages are:
  $12,12,13,12,13,12,10,13,12,11$
What is their mean age?  a s v d

e) The hourly wage of $5$ workers at Arms Factory are:
  £$8,$£$10,$£$14,$£$11,$£$13$
The hourly wage of $6$ workers at Bran Factory are:
  £$7,$£$13,$£$14,$£$10,$£$9,$£$10$
Which factory has a higher mean wage and by how much?  a s v d



Question 4


Find the missing piece of data in each of the following if their mean is $10$.

a) $9,\square,11$  a s v d
b) $6,\square$  a s v d
c) $\square,16,2$  a s v d
d) $25,\square,3,8,20,1$  a s v d
e) $4,5,6,7,8,9,\square,$  a s v d


Question 5


Find the missing piece of data in each of the following if their mean is $12$.

a) $12,\square,13$  a s v d
b) $0,\square$  a s v d
c) $15,16,13,\square,15$  a s v d
d) $13.5,\square,12.5,18.5,5.5,7.5$  a s v d


Question 6


Find the missing piece of data in each of the following if their mean is $6.6$.

a) $\square,6.6$  a s v d
b) $\square,10,3$  a s v d
c) $0,8.4,\square,4.2,10$  a s v d
d) $6.75,\square,2.2,8.25,9.8,16,0.5$  a s v d


Question 7


Find the mean of the following data set:

a)
Result Frequency
9 1
10 3
11 1
12 5
 a s v d
b)
Result Frequency
25 3
26 4
27 2
28 1
 a s v d
c)
Result Frequency
4 8
5 4
6 10
7 1
8 2
 a s v d


Question 8


Find the mean of the following (involves negative numbers):

a) $-4,-5,-9$  a s v d
b) $-16,-5,-20,-11$  a s v d
c) $-2,2$  a s v d
d) $-4,-2,3,11$  a s v d
e) $-10,0,15,-4,-6$  a s v d
f) $7,-7,8,-8,9,-9$  a s v d
g) $44,-6,8,-20,15,-35$  a s v d
h) $-72,84,22,-16,0,44,50,-204$  a s v d
i) $-125,215,-12,61,77,-821,521,22,124,-5,-124,13$  a s v d

j) $-5.2,7.3,-33,-3.6,-66,-12.7,22,5.94$  a s v d



Question 9


Find the missing piece of data in each of the following if their mean is $0$.

a) $\square,6$  a s v d
b) $12,\square,-1$  a s v d
c) $\square,32,-16,8,-4.4$  a s v d
d) $-6,20,\square,44,-18,-9,0$  a s v d


Question 10


Find the missing piece of data in each of the following if their mean is $-5$.

a) $\square,-2$  a s v d
b) $0,\square$  a s v d
c) $\square,4,8$  a s v d
d) $2,-5,\square,8,-10$  a s v d
e) $0.4,-4.3,\square,-4.5,-6.2,-9$  a s v d


Question 11


Answer the following worded questions:

a) Trule Inc. records how its profit over $5$ years:
  $\$44,000\quad\$50,000\quad\$12,000\quad\$60,000\quad\$15,000$
What was it's mean annual profit?  a s v d

b) Iota Inc. records how its profits/loss over $4$ years:
  $\$10,000\quad-\$16,000\quad\$34,000\quad-\$4,000$
Calculate the mean profit/loss over the $4$ years.  a s v d