Exam 1: Introduction to Statistics

Identify the type of observational study -A researcher plans to obtain data by following those in cancer remission since January of 2002.

Use critical thinking to address the key issue. -A company accused of downsizing workers defended itself with the following statement: "Yes, we were forced to lay off 20% of our workforce last year, but this year we increased our workforce by 20%, and we therefore now have the same number of employees as before the layoff." What is the flaw in this argument?

Identify the number -The number of limbs on a 2-year-old oak tree is 21.

Provide an appropriate response. -A market researcher obtains a sample of 50 people by standing outside a store and asking every 20th person who enters the store to fill out a survey until she has 50 people. What sampling method is being used here? Will the resulting sample be a random sample? Will it be a simple random sample? Explain your thinking.

which of these types of sampling is used -A town obtains current employment data by polling 10,000 of its citizens this month.