8MM Statistics Quiz

Checking every 30th box of chocolates on a production line to ensure quality and correct measurements is an example of

• Stratified sampling

• Random sampling

• Systematic sampling

• A survey

Answer explanation

There's a rule as to how they choose the chocolate boxes so it's systematic sampling.

The number of chairs in a classroom is an example of which kind of data?

• Numerical discrete

• Numerical continuous

• Categorical

• Census

Answer explanation

The number of chairs is a countable variable, therefore it's numerical and discrete.

If a score of 3 is added to the data in the dot plot, the median

• Increases by 1

• Remains the same

• Decreases by 1

• Decreases by 2

Answer explanation

Before the 3 is added, the median falls on the 8th data value, when another 3 is added the median falls on the 8.5th data value both of which are at score 3.

The average height of five students is 162 cm. If another student who is 168 cm joins the group, the new average height is:

• 162.5 cm

• 163 cm

• 164 cm

• 165 cm

Answer explanation

Sum of 5 students height = 162 x 5 = 810
Sum of 6 students height = 810 + 168 = 978
Average of 6 students = 978/6 = 163

The median of the numbers 8, 3, 5, 7, 10, 8, 3 is

• 3

• 5

• 7

• 8

Answer explanation

8, 3, 5, 7, 10, 8, 3

3, 3, 5, 7, 8, 8, 10
Median = 7

For the set of scores 1, 2, 3, 4, 4, 4, 5, 5, which measure is not 4?

• Mean

• Mode

• Median

• Range

Answer explanation

Mean = 28/8 = 3.5
Median (4.5th data value) = 4

Mode = 4

Range = 5 - 1 = 4

The mean of the numbers 4, 8 and x is the same as the mean of the numbers 4, 6, 8 and 10. Find the value of x.

• 6

• 7

• 8

• 9

Answer explanation

4, 6, 8 and 10 -> Mean = 28/4 = 7
4, 8 and x
(4 + 8 + x)/3 = 7 (as the means are the same)
12 + x = 21
x = 9

The mode is

• 2

• 3

• 4

• 5

Answer explanation

The mode is the score with the highest/largest frequency.

The mean to the nearest whole number is

• 2

• 3

• 4

• 5

Answer explanation

Mean = (4 + 10 + 21 + 24 + 15)/25 = 2.96

For the set of scores 5, 7, 3, 7, 6, 7, 9, 7, 8, 7, 7, 5, 3, find the difference between the median and the range.

• 0

• 1

• 2

• 3

Answer explanation

5, 7, 3, 7, 6, 7, 9, 7, 8, 7, 7, 5, 3
3, 3, 5, 5, 6, 7, 7, 7, 7, 7, 7, 8, 9
Median = 7
Range = 6
Difference = 1