Exam 6: Probability, Normal Distributions, and Z Scores

A researcher determines that students study an average of 80 20 (M SD)minutes per week.Assuming these data are normally distributed,what is the z score for students studying 60 minutes per week?

A researcher determines that students are active about 60 12 (M SD)minutes per day.Assuming these data are normally distributed,what is the z score for students being active 48 minutes per week?

In a hypothetical job field,10% of workers are promoted within their first year of employment.For this hypothetical job field,what is the probability that exactly 25 workers were promoted in their first year in a random sample of 200 workers? Hint: This is a binomial distribution,where p = .10 and q = .90.

A z score for the mean in a normal distribution is always equal to 0.

A counselor records the number of disagreements (per session)among couples during group counseling sessions.If the number of disagreements is distributed normally as 4.4 0.4 (M SD)disagreements,then what proportion of couples disagree at least 4 times during each counseling session?

An example of a binomial variable includes

Which of the following is an appropriate step for the normal approximation of the binomial distribution?

The standard deviation and the mean can equal 0 in a data set that is normally distributed.

Which of the following is required to locate z scores with a given proportion?

It is appropriate to use the normal approximation of the binomial distribution with a sample of 100 participants,where p = .07 and q = .93.

In a normal distribution with 2.2 4.1 (M SD),a researcher can appropriately conclude that most scores occurred above the mean.

Which of the following is required to locate proportions of area under the normal curve?

In a normal distribution with 3 1 (M SD),a researcher can appropriately conclude that about 84.13% of scores were greater than 2.

The first step to locating proportions in a normal distribution is to first look up probabilities in the unit normal table.

A standard normal distribution is a specific example of one of the infinitely possible normal distributions that could exist.

The mean,median,and mode are all located at the 50th percentile in a perfect normal distribution.

A theoretical distribution that evenly distributes data around the mean,median,and mode is called the

The ________ converts any normal distribution with any mean and any variance to a standard normal distribution with a mean of 0 and variance of 1.

The normal distribution is symmetrical,which means that

A distribution of z scores are distributed in what type of unit of measurement?