Exam 1: Introduction to Statistics

Use critical thinking to address the key issue. -A questionnaire is sent to 10,000 persons. 5,000 responded to the questionnaire. 3,000 of the respondents say that they "love chocolate ice cream". We conclude that 60% of people love chocolate ice cream. What is wrong with this survey?

Determine which of the four levels of measurement is most appropriate. -The temperatures of eight different plastic spheres.

Solve the problem. -Alex and Juana went on a 50-mile canoe trip with their class. On the first day they traveled 29 miles. What percent of the total distance did they canoe?

Provide an appropriate response. -Why do you think that cluster sampling is frequently used in practice.

Provide an appropriate response. -Explain the difference between stratified and cluster sampling.

Determine which of the four levels of measurement is most appropriate. -A stock analyst compares the relationship between stock prices and earnings per share to help him select a stock for investment.

Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a percent, if necessary. -Convert 49% to an equivalent fraction and decimal.

Identify the number -The average height of all freshmen entering college in a certain year is 68.4 inches.

Use critical thinking to address the key issue. -An airline company advertises that 100% of their flights are on time after checking 5 randomly selected flights and finding that these 5 were on time.

Determine which of the four levels of measurement is most appropriate. -Survey responses of "good, better, best".

Use critical thinking to address the key issue. -"7 out of 10 dentists recommend Brand X toothpaste". This finding is based on the results of a survey of 10 randomly selected dentists. What is wrong with this survey?

Determine which of the four levels of measurement is most appropriate. -A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish.

Determine which of the four levels of measurement is most appropriate. -A quality control specialist compares the output from a machine with a new lubricant to the output of machines with the old lubricant.

Determine which of the four levels of measurement is most appropriate. -Salaries of college professors.

Provide an appropriate response. -Describe a double blind experiment and explain why blinding is used. Define the term "placebo effect" as part of the answer.

Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a percent, if necessary. -Convert $0.4$ to an equivalent fraction and percentage.

Determine which of the four levels of measurement is most appropriate. -A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the drug has an effect on the patients' illness.

Determine whether the given value. -After taking the first exam, 15 of the students dropped the class.

Provide an appropriate response. -A researcher obtains a sample of high school teachers in his school district by randomly selecting 10 high schools and interviewing all the teachers at each of these 10 schools. What kind of sampling is being used here? Will the resulting sample be a simple random sample of the population of teachers in the school district? Explain your thinking.

Solve the problem. -On a test of 80 items, Ariel got 67 correct. What percent were correct?