Exam 6: Probability

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below. Answers below have been rounded to two decimal places.What is the probability that an individual has changed jobs or they have graduated from college?

There are no mathematical relationships among probabilities of simple events,conditional probabilities,and joint probabilities.

The method of sampling--with versus without replacement--never has an effect on the probability of observing some event.

A researcher wanted to compare eye color distributions of babies born with a birth defect with babies who did not have the birth defect.26 babies with the defect were matched on gender,race,and age with 52 babies without the defect.The frequency of different eye colors as a function of the presence or absence of the defects was as follows: Eye Color Group Dark Medium Light Defect 1 6 19 No Defect 15 13 24 What is the probability that a baby has dark eyes given that the baby has the birth defect?

If the size of the sample is small relative to the size of the population,sampling with versus without replacement will not affect probabilities appreciably.

What is an alpha level and how does it relate to hypothesis testing?

Suppose you are asked to toss 10 dimes and observe the number of heads.What is the likelihood of observing exactly 0 heads?

In hypothesis testing,if observations are unlikely to be due to chance,we ____________________the null hypothesis.

Sampling without replacement causes the probability of randomly selecting additional cases from that population to____.

Imagine you have five questionnaires you want to hand out to a group of people.What is the counting rule used to determine how many sets of five you have when ordering of the questionnaires does not matter?

A combination of a set of objects or events is an ordered sequence.

When selecting cases,putting each selected case back into the population before selecting another one refers to ____________________.

What does it mean to say that two events are independent?

In factorial notation,the expression 0! equals 1.

The probability of an event,A,is formally defined as the number of observations favoring event A divided by the:

The equation,p(A)= (number of observations favoring event A)/ (total number of observations)refers to the probability of a ____________________ event.

If the observed result of an investigation is similar enough to the outcome stated in the null hypothesis such that it can reasonably be attributed to chance,we will reject the null hypothesis.

In the use of the binomial expression for hypothesis testing,the initial assumption is that the frequency of the event will be equal to _____.

If our observations are so discrepant from the expected result that the difference cannot be attributed to chance,we will _____ the null hypothesis.

A sample of 500 people aged 30 - 40 years old were interviewed to study the relationship between whether a person graduated from college or only high school and whether s/he changed jobs in the last 5 years.The results are found in the contingency table below. Answers below have been rounded to two decimal places. Which of the following is a marginal frequency in the above table?