MATH 1010 Exam 3 Review Problems

Flashcards based on Exam 3 review problems.

What is the population in a study where a manufacturer wants to determine the average lifetime of its 75-watt light bulbs, and they test 120 randomly selected bulbs?

All 75-watt light bulbs manufactured by the company.

What is the sample in a study about stress levels among emergency-room nurses in the U.S., where 275 nurses are interviewed?

The 275 emergency-room nurses interviewed.

What is the sample statistic in a study where a bank manager polls 300 customers to find the average wait time?

The average wait time for the 300 customers polled.

What is the population parameter in a study where a bank manager polls customers to find the average wait time?

The average wait time for all the bank's customers.

What type of sampling is used when a market researcher randomly selects 500 drivers under 30 and 500 drivers over 30?

Stratified.

What type of sampling is used when a sample consists of every 20th student who leaves the library?

Systematic.

What type of sampling is used when a researcher interviews 19 work colleagues who work in his building?

Convenience.

What type of sampling is used when names are placed in a bag, and three names are picked?

Simple random.

What type of study is most appropriate to compare lawyers' versus doctors' salaries?

Observational study.

Which sample is most representative when determining the average weight of a house cat?

Some of the cats in each of several neighborhoods.

Which sample is most representative when determining the percentage of voters who favor stronger environmental laws?

A sample selected randomly from the phone book.

What does double blinding avoid in an experiment?

If an experimenter knows whether the patient has received the treatment or the placebo, this may influence how he or she questions the patient.

What type of experiment is it when patients don't know whether they are receiving the treatment or the placebo, but the experimenters do know?

Single-blind experiment.

What type of experiment is it when neither the participants nor the experimenters know which participants are in the control group?

Double-blind experiment.

Which measure of central tendency is affected by outliers?

The mean only.

Which quantity describes how widely data values are spread about the center of a distribution?

Variation.

Identify the distribution of lengths of human pregnancies.

Symmetric.

Identify the distribution of the number of siblings of adults in the U.S.

Right-skewed.

Identify the distribution of age at death for residents of the U.S.

Left-skewed.

Which distribution has the most variation: Salaries of CEOs, waitresses, bank clerks, or high-school teachers?

Salaries of CEOs of U.S. corporations.

Which distribution has the least variation: 100-meter times for male Olympic sprinters, male college seniors, adults, or college seniors?

100-meter times for male Olympic sprinters.

What method for determining probabilities did Melissa use when she estimates that the probability that she will marry her boyfriend is 0.6?

Subjective method.

What values could not possibly be probabilities?

Values less than zero or greater than one.

Which of the following events has a probability of 1?

I will die some day and the world will go on turning if I fail my test

How do you calculate the mean retirement age given employee ages at retirement?

Sum of the retirement ages divided by the number of employees.

How do you find the median for a given set of sample data?

The middle value when the data is arranged in ascending order.

What does the range represent for a given data set?

The difference between the highest and lowest values.

What values define the five-number summary for a given data set?

Minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum.

If you are given 6 roads connecting town A to town B and 4 roads connecting town B to town C. In how many ways can a person travel from A to C via B?

Multiply the number of roads: 6 * 4 = 24 ways

If a restaurant offers pizzas with 2 types of crust, 8 different toppings, and 5 different sizes, how many different pizzas could be ordered?

2 * 8 * 5 = 80 different pizzas

If a die with 6 sides is rolled. What is the probability of rolling a number less than 5?

Probability = 4/6 = 2/3