 New Zealand
Level 7 - NCEA Level 2

# Standard Deviation

## Interactive practice questions

Find the following based on this set of scores:

$19,18,14,19,10$19,18,14,19,10

a

Find the mean.

b

Complete the following table.

Score($x$x) $(x-$(xmean$)$) $(x-$(xmean$)^2$)2
$19$19 $\editable{}$ $\editable{}$
$18$18 $\editable{}$ $\editable{}$
$14$14 $\editable{}$ $\editable{}$
$19$19 $\editable{}$ $\editable{}$
$10$10 $\editable{}$ $\editable{}$
c

Thus, find the standard deviation, correct to 2 decimal places.

d

Find the range of the set of scores.

Easy
Approx 7 minutes

Consider the set of scores below:

$12,21,-9,-18,49$12,21,9,18,49

Find the population standard deviation of the following set of scores, to two decimal places, by using the statistics mode on the calculator:

$8,20,9,9,8,19,9,18,5,10$8,20,9,9,8,19,9,18,5,10

Find the population standard deviation of the following set of scores correct to two decimal places by using the statistics mode on the calculator:

$-17,2,-6,9,-17,-9,3,8,5$17,2,6,9,17,9,3,8,5

### Outcomes

#### S7-4

S7-4 Investigate situations that involve elements of chance: A comparing theoretical continuous distributions, such as the normal distribution, with experimental distributions B calculating probabilities, using such tools as two-way tables, tree diagrams, simulations, and technology.

#### 91267

Apply probability methods in solving problems