Statistics Quiz

The following information is collected from an application form: (i)marital status (ii) monthly expenditure (Rands) (iii) number of qualifications completed (iv) gender Which of the above variables are quantitative?

• (i) and (ii)

• (ii) and (iii)

• (iii) and (iv)

• (i) and (iv)

Which of the following statements is false?

• Ordinal variables can be ranked.

• In a designed experiment the experimenter can control the experiment to a certain extent.

• In simple random sampling, each sample of a given size (n) has an equal probability of being selected.

• The term 'population' refers only to people.

A zookeeper wishes to proportionally sample 120 animals from a population of 750 animals in a zoo. Four hundred (400) of the animals are classified as friendly, 300 as shy and the rest as dangerous. There is no animal that falls into more than one category. Using stratified sampling, what is the sample size for the dangerous stratum?

• 64

• 48

• 8

• 50

Which of the following statements is true about the concept of probability?

• Probability is a measure of the likelihood of an event occurring, and it can take on any value between 0 and 1.

• Probability is a measure of the frequency of an event occurring, and it can only take on integer values.

• Probability is a measure of the likelihood of an event occurring, and it can only take on values of 0 or 1.

• Probability is a measure of the frequency of an event occurring, and it can take on any value between 0 and 1.

Which of the following types of sampling methods is most likely to result in a biased sample?

• Simple random sampling

• Stratified sampling

• Convenience sampling

• Cluster sampling

What type of sampling method is used when a researcher selects participants based on specific characteristics, such as age or gender?

• Simple random sampling

• Stratified sampling

• Convenience sampling

• Cluster sampling

What is the purpose of a box plot?

• To display the mean and standard deviation of a dataset

• To show the distribution of a dataset

• To compare the means of two datasets

• To display the correlation between two variables

A researcher conducts a study on the effect of exercise on blood pressure. What type of study is this?

• Experimental study

• Observational study

• Survey study

• Case study

What is the difference between a population and a sample?

• A population is a subset of a sample

• A sample is a subset of a population

• A population is a group of people, while a sample is a group of data points

• A sample is a group of people, while a population is a group of data points

A survey of 20 students found the following numbers of hours spent watching TV per week: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40 What is the probability that a randomly selected student watches more than 25 hours of TV per week?

• 0.2

• 0.3

• 0.4

• 0.5