New Zealand

Level 7 - NCEA Level 2

The mean of a set of scores is $77$77 and

the standard deviation is $29$29. Find the value of:

a

$\text{Mean }-\text{Standard Deviation}$Mean −Standard Deviation

b

$\text{Mean }+2\times\text{Standard Deviation}$Mean +2×Standard Deviation

c

$\text{Mean }-\frac{\left(2\times\text{Standard Deviation}\right)}{3}$Mean −(2×Standard Deviation)3

d

$\text{Mean }+\frac{\left(4\times\text{Standard Deviation}\right)}{5}$Mean +(4×Standard Deviation)5

e

$\text{Mean }+3\times\text{Standard Deviation}$Mean +3×Standard Deviation

f

$\text{Mean }-2\times\text{Standard Deviation}$Mean −2×Standard Deviation

Easy

Approx 4 minutes

The mean of a set of scores, denoted by $\mu$`μ`, is $51$51 and

the standard deviation is $16$16, and is denoted by $\sigma$`σ`. Find the value of:

The literacy rate of a population is used to help measure the level of development of a country. The average literacy rate in a particular country is $59%$59%, and the standard deviation is $5%$5%. The literacy rate varies from place to place within the country.

The following table shows the marks obtained by a student in two subjects.

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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.

Apply probability methods in solving problems