Exam 6: Probability, Normal Distributions, and Z Scores

A researcher wants to know the probability of being named on the honor roll from a population where 8% of students are on the honor roll.If the researcher selects a sample of 400 students,then what is the mean number of students expected to be on the honor roll? Hint: This is a binomial distribution,where p = 0.08 and q = 0.92.

A therapist has a goal to reduce the mean number of patient symptoms expressed for a particular disorder to two symptoms per day.Following therapy,she determines that the z score for 2 symptoms per day is 0.Assuming the data are normally distributed,did she reach her goal?

The normal distribution has all of the following characteristics,except that

A professor finds that the students scored a 76 8 (M SD)on the final exam.On this exam,a score of 90 is an A.Assuming these data are normally distributed,what is the z score for 90 (the cutoff for an A)?

What is the z score for scores in the top and bottom 2.5%?

In a normal distribution,50% of all data:

A researcher records the following times (in seconds)that it took a group of students to complete an exam: 18±2 minutes (M±SD).How long did it take 80% of students to complete the exam?

The standard normal distribution can be used to estimate probabilities with known raw scores,but it cannot be used to estimate raw scores with known probabilities.

Which of the following is not a step to locate a score in a normal distribution?

The ________ are the range of continuous values containing the score of interest in a binomial distribution.

The total area under a normal curve increases as the standard deviation increases.

A researcher wants to know the probability of selecting a student athlete from a school population where 5% of students are athletes.If the researcher selects a sample of 120 students,is it appropriate to use the normal approximation of the binomial distribution to estimate this probability?

Most behavior is believed to ________ a normal distribution.

In a normal distribution a score of 8 will always be more probable than a score of 0.

When a z score equals 0,this means that there is no variability.

Scores far from the mean are located in the ________ of a normal distribution.

Another name for a binomial variable is a

The unit normal table can be used to find the probability of a particular score in both normal and nonnormal distributions.

Which of the following is a possible value for the standard deviation of a normal distribution?

The unit normal table can be used to find the probability of a particular score for most,but certainly not all,possible normal distributions.