Question 1

Which of the following best describes the difference between a parameter and a statistic?

Accepted Answer

A parameter is a numerical summary of a population, while a statistic is a numerical summary of a sample.

Question 2

A researcher wants to study the effect of a new drug on blood pressure. She randomly assigns participants to either receive the drug or a placebo and measures their blood pressure after treatment. What type of study is this?

Accepted Answer

Designed experiment

Question 3

Which of the following is an example of a discrete variable?

Accepted Answer

The number of cars owned by a family

Question 4

In the context of sampling, what is the main advantage of using a simple random sample?

Accepted Answer

It gives every possible sample of size $$n an $$equally likely chance of being chosen.

Question 5

A physical therapist records the body part requiring rehabilitation for 30 patients. She organizes the data into a frequency distribution. What type of variable is she working with?

Accepted Answer

Qualitative variable

Question 6

Which sampling technique involves dividing the population into nonoverlapping groups and then taking a simple random sample from each group?

Accepted Answer

Stratified sampling

Question 7

A survey is conducted by selecting every 10th person from a list of 1,000 employees. What sampling method is being used?

Accepted Answer

Systematic sampling

Question 8

Which of the following is a source of response bias in a survey?

Accepted Answer

The wording of questions influencing answers

Question 9

A study finds that people who exercise regularly are less likely to develop heart disease. However, the study did not account for diet. What is diet in this context?

Accepted Answer

A lurking variable

Question 10

Which of the following best describes a matched-pairs design?

Accepted Answer

Experimental units are paired based on similarity, and each pair receives both treatments.

Question 11

A frequency distribution is constructed for the number of customers arriving at a restaurant during 40 intervals. The relative frequency for 6 customers is $$0.275. $$What percentage of intervals had 6 customers?

Accepted Answer

$$0.275 	imes 100 = 27.5\%$$

Question 12

Which of the following graphs is most appropriate for displaying the distribution of a qualitative variable?

Accepted Answer

Bar graph

Question 13

A pie chart is used to represent data. What does the area of each sector correspond to?

Accepted Answer

The frequency or relative frequency of the category

Question 14

When organizing continuous quantitative data into classes, how is the class width determined?

Accepted Answer

By subtracting the smallest value from the largest and dividing by the number of classes, then rounding up.

Question 15

Which of the following distributions is described as 'skewed right'?

Accepted Answer

The tail to the right of the peak is longer than the tail to the left.

Question 16

In a cumulative frequency distribution for continuous data, what does the cumulative frequency for a class represent?

Accepted Answer

The total number of observations less than or equal to the upper class limit.

Question 17

A researcher wants to compare the educational attainment of adults in 1990 and 2021. Which type of graph should she use to compare the two data sets, given that the sample sizes are different?

Accepted Answer

Side-by-side bar graph using relative frequencies

Question 18

Which of the following is NOT a source of bias in sampling?

Accepted Answer

Random sampling

Question 19

In a double-blind experiment, who is unaware of which treatment is being administered?

Accepted Answer

Both the experimental unit and the researcher monitoring the subject

Question 20

Which of the following best describes a frequency polygon?

Accepted Answer

A graph that uses points connected by line segments to represent frequencies for classes

Introductory Statistics: Collecting, Organizing, and Summarizing Data

Guida di studio - Domande di pratica

Study guide - Flashcard