Q: A company surveyed 374 employees. If 42.1% of the employees surveyed were females, how many males were surveyed?

$$374 - (0.421 \times 374) = 216$$

Question 1

A survey of 619 subjects was conducted by posting a question on a website and collecting responses from internet users. Which of the following best describes a major flaw in this sampling method?

Accepted Answer

It is flawed because it is a voluntary response sample.

Question 2

Which of the following is NOT classified as a potential pitfall when analyzing survey data?

Accepted Answer

Measured data

Question 3

Seventy percent of all Ninth-Grade students passed their final exam. Is this value a statistic or a parameter?

Accepted Answer

Parameter

Question 4

Which of the following best describes the relationship between a sample and a population?

Accepted Answer

Sample; Population

Question 5

People are asked how many kids they have. Is the resulting data discrete or continuous?

Accepted Answer

Discrete

Question 6

The time it takes to run a marathon is recorded for each participant. Is this data discrete or continuous?

Accepted Answer

Continuous

Question 7

Students' grades (A, B, or C) on a test are recorded. Which level of measurement is most appropriate for this data?

Accepted Answer

Ordinal

Question 8

A survey asks respondents to rate their level of satisfaction. What is the most appropriate level of measurement for this variable?

Accepted Answer

Ordinal

Question 9

The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag. What type of sampling is this?

Accepted Answer

Simple random

Question 10

A company surveyed 374 employees. If 42.1% of the employees surveyed were females, how many males were surveyed?

Accepted Answer

$$374 - (0.421 	imes 374) = 216$$

Question 11

A doctor gives a new medication to half of his patients with the flu and a placebo to the other half. Is this an observational study or an experiment?

Accepted Answer

Experiment

Question 12

Given the following class limits for home sale prices: $$70.0-90.9$$, $$91.0-111.9$$, $$112.0-132.9$$, $$133.0-153.9$$, $$154.0-174.9$$, $$175.0-195.9$$, what is the class width?

Accepted Answer

$$91.0 - 70.0 = 21.0$$

Question 13

A frequency distribution for car speeds is given as: 0-19 (6 cars), 20-49 (18 cars), 50-79 (56 cars), 80-109 (30 cars). What is the cumulative frequency for 'Less than 80'?

Accepted Answer

$$6 + 18 + 56 = 80$$

Question 14

A nurse measures the blood pressure of each person who visited her clinic. If the relative frequency histogram shows that 25% of people aged 25-40 had a systolic blood pressure between 130 and 139 mm Hg inclusive, what does this percentage represent?

Accepted Answer

The proportion of people in the sample with systolic blood pressure between 130 and 139 mm Hg.

Question 15

A histogram represents the number of television sets per household for a sample of U.S. households. The frequencies are: 20, 50, 15, 10, 5. What is the sample size?

Accepted Answer

$$20 + 50 + 15 + 10 + 5 = 100$$

Question 16

A frequency distribution of low temperatures for a 31-day month is approximately symmetric and bell-shaped. What does this suggest about the distribution?

Accepted Answer

The distribution is approximately normal.

Question 17

A store manager counts the number of customers who make a purchase each day. The data are: 10, 11, 8, 14, 7, 10, 11, 8, 7. Which type of plot would best display the frequency of each value?

Accepted Answer

Dotplot

Question 18

Attendance records at a school show the number of days each student was absent during the year: 0, 1, 3, 2, 4, 4, 2, 3, 5, 4, 2, 5. What is the correct way to arrange the data for a dotplot?

Accepted Answer

0, 1, 2, 2, 2, 3, 3, 4, 4, 4, 5, 5

Question 19

The weights (in lb.) of 22 members of a junior varsity football team are listed. Which measure of central tendency would be most affected if one member's weight was incorrectly recorded as 300 lb instead of 150 lb?

Accepted Answer

Mean

Fundamental Concepts and Methods in Statistics: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard