Exam 6: Characteristics of the Sample Mean

A researcher selected data that were normally distributed,and appropriately concluded that about 68.26% of scores occurred within one standard deviation of the mean.

The unit of measurement distributed along the x-axis of a standard normal distribution is referred to as a

State whether the first area is bigger,the second area is bigger,or the two areas are equal: the area to the left of z = 1.00,or the area to the left of z = -1.00.

Most behavior is believed to ________ a normal distribution.

State whether the first area is bigger,the second area is bigger,or the two areas are equal: the area to the left of z = 0.80,or the area to the right of z = -0.80.

The normal distribution is symmetrical,which means that

Most behavioral phenomena are believed to approximate the normal distribution.

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 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?

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?

For a set of data with 25±2.5,at least 95% of scores fall between 20 and 30.

What is the z score for scores in the bottom 10%?

The following distribution most closely approximates a

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

Data were normally distributed as 3.6 0.6 (M SD).Hence,69.15% of data occurred below a score of 3.9 in this distribution.

A researcher records the following times (in seconds)that it took a group of mice to complete a maze: 23 4.1 (M SD).The top 10% of mice finishing with the fastest times will be placed in a "maze bright" group.What is the cutoff time to be placed in this group?

A researcher finds that the average preschool-aged child drinks two cups of milk per day.Assuming these data are normally distributed,the z score for the average cups per day in this example is

The closer a z score is to 0,the smaller the area is under the normal curve toward the tails.

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

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