Show:
The z Table 1
The z Table 2
Hypothesis Testing 1
Hypothesis Testing 2
z Test
100
To determine a person's percentile, first convert the person's raw score to a:
z score.
100
In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. The professor tells Mackenzie she scored at the 44th percentile. How many hours does she study per week? (Round z score to two decimal places.)
9.24 hours
100
The distribution of means has the same mean as the distribution of scores for the population, and the spread is:
smaller.
100
One rejects the null hypothesis when the test statistic falls in which area of the distribution?
critical region
100
The statement "It is hypothesized that children who attend an enrichment program will score higher on IQ tests compared to children who do not attend an enrichment program" best illustrates a ____-tailed test:
one-tailed test.
200
In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. Treating this class as the population, what is the percentile for a student in the class who studies 8 hours a week? (Round z score to two decimal places.)
33.72
200
India converts her raw score on a memory scale to a z score and finds that her score corresponds to a z score of Ð0.92. She knows her score is below the mean. What percent of people scored lower than India on the memory scale?
17.88%
200
Inferential statistical analyses that are NOT based on a set of assumptions about the underlying population are:
nonparametric tests.
200
The null hypothesis states that:
there are no differences between the populations being studied.
200
The statement "It is hypothesized that men and women will differ on reaction time measures" best illustrates a ____-tailed test:
two-tailed test.
300
In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. Treating the class as the population, what is the percentile for a student in the class who studies 10 hours a week? (Round z score to two decimal places.)
50.8
300
Demi converted scores from a customer service questionnaire to z scores, and some of them are negative. She is trying to use a z table but is confused because there are no negative z scores in the tables. What should she do?
Use the positive value because the normal curve is symmetric.
300
_____ requires that all members of a population have an equal chance of being selected for a study.
Random selection
300
The _____ level is the probability used to determine the critical values, or cutoffs, in hypothesis testing.
p
300
The critical value(s) associated with a p level of 0.05 for a two-tailed hypothesis test using the z statistic is (are):
-1.96 and 1.96.
400
To determine a person's percentile, first convert the person's _____ score to a z score.
raw
400
Atif has a z score of 1.02 from a converted IQ score. From a z table, the percentage between his score and the mean is 34.61 percent. What percent of people have IQs at or lower than Atif's score?
84.61
400
Because of the principle of _____ theorem, when sample sizes are at least 30, the distribution will most likely resemble a normal distribution.
the central limit
400
The _____ hypothesis is usually the "boring" one.
null
400
The statement "It is hypothesized that students will score higher on their test during the morning hours compared to the afternoon hours" best illustrates an example of a _____-tailed test.
one-tailed test.
500
In one statistics course, students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. Mark studies 16 hours per week. What percent of students are at least as extreme as Mark, in both directions? (Round z score to two decimal places.)
9.01
500
(T/F) The z table only allows for the calculation of percentiles for positive z values.
FALSE
500
The _____ hypothesis is usually the "exciting" one.
research
500
The typical probability adopted by researchers to determine whether a result is extreme is:
0.05.
500
The critical value(s) associated with a p level of 0.05 for a one-tailed hypothesis test using the z statistic is (are):
-1.65 and 1.65.