Question

Health SurveyIn a survey of 1020 adults in the United States, 44% said that they wash their hands after riding public transportation (based on data from KRC Research).

a. Identify the sample and population.

b. Is the value of 44% a statistic or parameter?

c. What is the level of measurement of the value of 44%? (nominal, ordinal, interval, ratio)

d. Are the numbers of subjects in such surveys discrete or continuous?

Short answer

1. The group of 1020 adults selected for the survey is the sample, and the group of the entire adult population of the United States is the population.

2. The percentage of adults equal to 44% is a statistic.

3. The value of the statistic equal to 44% is measured on the ratio level.

4. The subjects in such surveys are the number of individuals/adults and hence are discrete.

Step-by-step solution

Given information

A sample of 1020 adults in the United States is surveyed.

The percentage of adults from the sample who said they wash their hands after riding public transportation is equal to 44%.

Definition of important terms

Apopulationis the set of all individuals under consideration about which we want to gain insights.

Asample is a sub-group selected from the population.

Aparameter is a statistical quantity computed from the population. For example, mean, range, proportion, etc.

Astatistic is a statistical quantity computed from the sample.

The level of measurement of a variable shows the precision of the values of that variable. They are four in number:

• Nominal: All categorical data are nominal. This is the least refined scale. For example, assigning numbers to categories like 1 to Red, 2 to Blue, 3 to Green, etc.

• Ordinal: On an ordinal scale, data can be arranged in order, but the values' differences are not meaningful. This is one level higher in precision than the nominal scale. For example, ranks are assigned to students based on performance level.
• Interval: On an interval scale, differences between the values can be computed, but the ratios have no meaning. There is no true – zero value for this type of data. Examples include temperature, pH level, etc.

• Ratio: Data with values whose ratios can be computed, and true – zero value exists can be measured on a ratio scale. This is the most refined scale. For example, length, amount of water, height, etc.

Discrete data is quantitative data that holds countable fixed values. For example, the number of tails that appeared in successive tosses of a coin, the number of road accidents, etc.

Continuous data is quantitative data that holds uncountable values (including integral as well as fractions). For example, wind speed, temperature, etc.

Identification of different types of data

1. The entire adult population of the United States from which the sample is chosen is the population. The selected group of 1020 adults forms the sample.

2. The percentage of adults who wash their hands is equal to 44%. It is a statistic computed from the sample of 1020 adults.

3. As the percentage of the number of adults who wash their hands is a ratio, and its true-zero value is meaningful; hence the value of 44% is measured at the ratio level.

4. Here, the subjects are the adults of the United States who can be easily counted. Therefore, they are discrete.