Question 1

A survey conducted by the American Automobile Association (AAA) asks members about their use of public transportation. Which of the following best describes a potential source of bias in this survey?

Accepted Answer

There is a potential for bias because AAA members may have different transportation habits than the general population.

Question 2

A study at several universities examines the potential link between brain size and intelligence. Which of the following is a potential source of bias in this study?

Accepted Answer

There is a potential for bias if the sample only includes students from prestigious universities.

Question 3

A newspaper posts an online poll asking, 'In your view, are nuclear plants safe?' What is the main flaw in the sampling method?

Accepted Answer

It is flawed because it is a voluntary response sample.

Question 4

A weight loss program claims that participants lost an average of 10 kg. The probability of this result occurring by random chance is 2%. Is this result statistically significant?

Accepted Answer

Yes, the program is statistically significant because the results are unlikely to occur by chance.

Question 5

In a study of all 409 students at a college, it is found that 40% watch television daily. Is this value a statistic or a parameter?

Accepted Answer

Parameter, because the value is a numerical measurement describing a characteristic of a population.

Question 6

The salaries of all state governors are collected and analyzed. Are these data qualitative or quantitative?

Accepted Answer

The data are quantitative because they consist of counts or measurements.

Question 7

The numbers of children in families are recorded for a study. Are these data discrete or continuous?

Accepted Answer

The data are discrete because the data can only take on specific values.

Question 8

A homeowner measures the voltage supplied to his home on 259 days of a given year, and the average (mean) value is 109.8 volts. Is this value a statistic or a parameter?

Accepted Answer

The given value is a statistic for the year because the data collected represent a sample.

Question 9

The sinking of the Titanic in 1912 resulted in a population of 1503 passengers and crew. If the average age of the victims is calculated, is this value a statistic or a parameter?

Accepted Answer

The value is a parameter because it describes some characteristic of a population.

Question 10

In a study of hospitals in one state, it was found that the average (mean) weight at birth was 3197.6 grams. Is this value a statistic or a parameter?

Accepted Answer

The value is a statistic because it describes some characteristic of a sample.

Question 11

In a study of all 2812 employees at a college, it was found that 45% commute by vehicle. Is this value a statistic or a parameter?

Accepted Answer

Parameter, because the value is a numerical measurement describing a characteristic of a population.

Question 12

The numbers of different sizes offered by various clothing manufacturers are recorded. Are these data discrete or continuous?

Accepted Answer

The data are discrete because the data can only take on specific values.

Question 13

The exact lengths (in kilometers) of ocean coastlines of different countries are recorded. Are these data discrete or continuous?

Accepted Answer

The data are continuous because the data can take on any value in an interval.

Question 14

Livability rankings for cities are recorded. Which level of measurement is most appropriate?

Accepted Answer

Ordinal

Question 15

Mood levels of 'happy', 'alright', and 'sad' are recorded. Which level of measurement is most appropriate?

Accepted Answer

Ordinal

Question 16

Ratings of hotels on a scale from 0 stars to 4 stars are recorded. Which level of measurement is most appropriate?

Accepted Answer

Ordinal

Question 17

Years in which a war started are recorded. Which level of measurement is most appropriate?

Accepted Answer

Interval

Question 18

Refer to the table summarizing service times (seconds) of dinners at a fast food restaurant. If the midpoint of the class 120dash179 is 149.5 seconds, what is the formula for calculating the midpoint of any class interval?

Accepted Answer

$$ 	ext{Midpoint} = \frac{	ext{Lower class limit} + 	ext{Upper class limit}}{2} $$

Elementary Statistics: Key Concepts, Data Types, and Measurement Levels

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