New Zealand
Level 8 - NCEA Level 3

# Sample Proportions (calculating and comparison)

## Interactive practice questions

From a sample of $400$400 young workers in Seattle, $37$37 had amber eyes.

What is the sample proportion of amber eyes for young workers in Seattle?

Easy
Less than a minute

A manufacturer of cement trucks checked some of the cement trucks being distributed for faults. On one day, $75$75 cement trucks were checked and $16$16 of these were found to have some kind of fault.

What was the sample proportion for faulty cement trucks?

At an electronics store, cameras are sold at prices ranging from $\$150$$150 to \630$$630. On a particular day, there are $106$106 cameras on sale and $25$25 of these cost less than $\$260$$260. If Irene came into the store and selected a camera at random, estimate the probability that camera would cost less than \260$$260.

A survey of $115$115 randomly selected people in Busan found that $6$6 of them were aged over $55$55.

A second survey of $2183$2183 randomly selected people in Busan found that $475$475 of them were aged over $55$55.

### Outcomes

#### S8-2

Make inferences from surveys and experiments: A determining estimates and confidence intervals for means, proportions, and differences, recognising the relevance of the central limit theorem B using methods such as resampling or randomisation to assess

#### 91582

Use statistical methods to make a formal inference