Final Exam- BS

For a particular group of scores, M=20, SD= 5. What is the Z scores of raw score of 10. A. -2 B. 0 C. -1 D. 2

-2

In a distribution of z-scores. The mean is always A. 10 B. 50 C. 1 D. 0

0

The standard deviation of a group of scores is 4. What is the variance? A. 4 B. 16 C. 8 D. 2

16

Approximately what percentage of scores are between the mean and one standard deviation below the mean on a standard normal curve? A. 50% B. 34% C. 16% D. 14% I?jj

16%

The mean score on a creatively test is 20 and the standard deviation is 5. The distribution is normal. Using the 50-34-14 rule as an estimation tool, which percentage of people would attain a score between 15 and 25 A. 34% B. 34% + 34% = 68% C. 50% D. 14% + 34% = 48%

34% + 34% = 68%

For a particular group of scores M=15 and SD=3. Provide a raw score for a z scores of 7. A. 15 B. 36 C. 24 D. 48

36

An analysis of variance produces SS total=40 and SS within=10. For this analysis what is SS between? A. 30 B. 50 C. 400 D. cannot be determined

A. 30

IN ANOVA, the ratio of the between groups variance to the within-groups is known as the A. F ratio B. T-ratio C. ANOVA ratio D. G ratio

A. F ratio

When a distribution is heavily tailed, means A. Has flat appearance with many scores at the extreme (tails) B. Skewed to the left C. Has pinched appearance with few scores at the extreme (tail) D. Skewed to the right

A. Flat appearance with many scores at the extreme (tails)

One typical way to determine which groups are different in an ANOVA design is to perform a A. planned comparison B. t-test for post ANOVA C. t-test for dependent ANOVA pairs D. preferred t-test

A. Planned comparison

Which set of sample characteristics will most likely produce a significant t-score? A. a large sample size and small sample variance. B. a large sample and a large sample variance. C. a small sample size and a small sample variance. D. small sample size and a large sample variance.

A. a large sample size and small sample variance.

Each of the following is part of conducting t-test for independent means except: A. difference scores are found for each participants. B. the population variance are estimated. C. comparison is made against a t-distribution D. The variance of the distribution of differences between means is figured.

A. difference scores are found for each participants

The mean of a distribution of sample means is: A. The original population mean divided by the sample size. B. The sample mean multiplied by the variance. C. The same as the original population mean. D. The square root of the original population mean.

A. original population mean divided by sample size

The variance of a distribution of means of samples of more than one is: A. Smaller than the original population variance. B. unrelated to the original population variance C. Greater than the original population variance. D. The same as the original population variance.

A. smallerthan the original population variance

A very small treatment effect can still be significant if: A. The sample size n is very large. B. The population standard deviation mean is very large. C. The standard error SE is very large. D. All of the above

A. the sample size is very large

If a sample has 27 people in it, the degrees of freedom used in the formula for estimating population variance would be: A. 26 B. 27 C. 27^2 D. square root of 27

A.26

If the null hypothesis is true and there is no treatment effect, what value is expected on average for the F ratio? A. 0 B. 1 C. k-1 D. N-k

B ?

In which situation would you use a t-test for dependent means? A. To compare the level of honesty in politicians to the level of honesty in students. B. To compare of the level of reading comprehension of students at the beginning of a speed-reading class tot heir level of reading comprehension at the end of the class. C. To find the correlation between liking of coffee and tendency to be a "night person" among a group of students. D. To compare the scores on a tolerance-of-diversity measure between two sororities.

B.

What is the main difference between z-scores and t-score? A. t-scores are used when study requires a one-tailed test. B. t-scores are used when the population variance is unknown. C. t-scores are used whenever the sample size is greater than 30. D. t-scores are used only when inferences are made about other samples.

B.

Which of the following is an example of a situation of which you should on duct a t-test for INDEPENDENT MEANS? A. A comparison of the SAT scores for a group of 10 students who completed a special SAT preparation course compared to how people do on the SAT in general. B. A comparison of scores of participants in memory study in which one group learns the words in alphabetical order and another group learns the words in order of word length. C. A comparison of participants scores on a skills test before and after attending a training session for improving the skill. D. None of the above would be suitable for a t-test for independent means

B.

In the formula for computing standard deviation of a sample, the sum of squared devation (SS) is divided by: A. The number of participants in the sample. B. The number of participants in the sample minus one. C. The number of participants in the population. D. The number of participants in the population minus one.

B. # of participants in the sample minus one

For a two tailed test at the 0.05 significance level, the appropriate cutoff z-scores would be: A. +/- 2.58 B. +/- 1.96 C. +/- 2.33 D. +/- 1.64

B. +/- 1.96

With a t-test for dependent means, the expected difference score for the null hypothesis will typically be: A. -1 B. 0 C. +1 D. it varies from sample to sample.

B. 0

An analysis of variance produces df between =3 and df within=24. For this analysis, what is DFtotal? A. 26 B. 27 C. 28 D. cannot be determined without information

B. 27

An ANOVA produces SS between =40 and MS between= 10. in this analysis how many treatment groups are being compared? A. 4 B. 5 C. 30 D. 50

B. 5

IN an ANOVA, if the within groups variance is about the same as the between groups variance then: A. the null hypothesis should be rejected. B. any difference between sample means is probably due to random sampling C. An error in the calculations we made because the within groups variance must always be smaller than the between group variance. D. any difference between sample means is probably due to a real difference caused by the experimental manipulations

B. Any difference between

Which of the following will increase the power of a hypothesis test? A. Change alpha from .05 to .01. B. Change the sample size from 25 to 100. C. Change from a one tailed to a two tailed test. D. None of these options increase power.

B. Change the sample size from 25 to 100

In a histogram, the vertical dimension displays A. Possible values the variables can have. B. Frequency C. mean score D. Intensity of variable

B. Frequency

In some cases, researchers describe a distribution in terms of whether tails have many of few scores in them. This aspect of shape of a distribution is know as A. Queue B. Kurtosis C. Symmetry D. 2 transformation

B. Kurtosis

A Canadian political scientist discovers that the numbers of members of members of their panlament that a group of voters can name as follow, 3,3,3,4,4,5,6,7,8,9,10,111,35 upon examination of these scores the researchers would probably decide to use which measure of typical value? A. Mode B. Median C. Standard Deviation D. Mean

B. Median

Which of the following is an example of an equal-interval variable? A. Results of horse race (1,2,3, etc) B. Number of friends a person has (2, 4, 6) C. Marital status. D. Numbers printed on the back of basketball teams jersey.

B. Number of friends a person has.

Suppose you wish to compare three medical treatment for bipolar disorder (treatments a,b,c) the null hypothesis would be that: A. several populations being compared all have different means B. several populations being compared all have the same mean C, true population variance differ by a factor of 10 D. true populations variance differ by factor of sample size

B. Several populations being compares all have the same mean.

All of the following are examples of RANK ORDER variable except.. A. Tennis player compared to other athletes. B. Students level of stress. C. Runners place finished in a race. D. Rank in graduating class.

B. Students level of stress.

Suppose you have three groups (ABC) Where you reject the null hypothesis is an ANOVA, this tells you that the population means: A. are equivelant B. are not the same C. are different and in which directions (e.g A>B>C) D. are related by virtue of their modal scores

B. They are not the same.

Failing to reject the null hypothesis when the research hypothesis is true is referred to as: A. The error term. B. Type 1 error. C. The probability of rejection. D. Type II error.

B. Type 1 error

A researcher's rates participants empathic response to the distress of strangers on a scale of 1 to 10. Most participants were either 3 or 7. How would the distribution be described? A. rectangular B. Bimodal C. Normal D. unimodal

B. bimodal

An analysis of variance (ANOVA) differs from an independent samples t-test in that an ANOVA A. usually used to compare the means of two groups but a t-test is used to compare 3 groups. B. is used to compare the means of three or more groups whereas t-test is used to compare two groups. C. is conducted after experiment whereas t-test is conducted after the experiment. D figures as part of the analysis whereas a t-test does not figure variance.

B. is used to compare the means of three or more groups whereas ttest is used to compare two groups

The standard deviation of the distribution of sample means is also known as the: A. population standard deviation B. standard error of the population. C. Standard error o the mean. D. Variance of the error mean.

B. standard error of population

In an independent samples hypothesis test, if t=0, then A. The two populations means must be equal B. the two sample means must be equal C. the two sample variance must be equal D. none of the above is correct

B. the two sample means must be equal

In general, increasing the sample size (for example, from n=4 to n=50) will ____ the risk of a Type I error (assuming alpha is held constant at 0.05)? A. Increase B. Decrease C. Have no influence on. D. Cannot be determined.

B.decreases

Cohens (1988) conventions of r^2 are as follows for small, medium, and large effect sizes: A. 00.2, 0.5, .08 B. 0.1, 0.4, .0.9 C. 0.01, 0.06, .14 D. 0.001, 0.5, 0.1

C. 0.01, 0.06, 0.14

An independent samples experiment use one sample with n=6 and a second sample with n=10 to compare two experiemental treatments. The statistics from the experiment will have degree of freedom from equal to: A. 7 B. 5 C. 14 D. 15

C. 14

A researcher reports t(24)=5.3 for an independent samples experiment. How many individuals participated in the entire experiement? A. 24 B. 25 C. 26 D. 12

C. 26

When a distribution is positively skew, it means A. There is a ceiling effect B. More scores piled up at high end of range C. More scores piled up at low end of range D. Evenly distributed

C. More scores are piled up at the low end of range

In a histogram, the horizontal dimension displays A. Mean scores B. Percentile scores for each individual. C. Range of possible values the variable can have.. D. Frequency

C. Range of possible values the variable can have.

Setting the significance level at a very extreme cutoff (Such as 0.001) increase the chance of: A. Getting a significant result. B. Type 1 error C. Type 2 error D. Rejecting the null hypothesis

C. Type II error

Suppose you conduct a study in which you set the significance level cutoff at a lenient probability level, such as 15%. In this case, you would have a 15% chance of making a: A. Computational error B. Type I error C. Type II error D. Type III error

C. Type II error

A psychologist is interested in studying aggressive tendencies in people and develops a measure of this personality characteristic. Aggression has become a ____ in the psychologists' study A. Invariable construct B. Abstract concept C. Variable D. Value

C. Variable

When a researcher has obtained a particular sample mean from a study, he/she compares it to: A. The distribution of means that would arise if the null hypothesis were true. B. The parameters of the known population distribution. C. An estimated distribution figured based on earlier research findings. D. The distribution of means of all the possible samples in the experimental condition from the research.

C. an estimated distrubtion

You do a t-test for dependent means in exactly the same way as a t-test for a single sample, except that you use something called: A. the mean variance B variance of dependent means. C. difference scores D. Independent t-scores

C. difference of scores

If a researcher reports a single-sample t-statistics with df=20 how many individuals were in the sample? A. n=19 B. n=20 C. n=21 D. cannot be determined from the information given.

C. n=21

In a t-test for independent means, the weighted average of the estimate of the population from samples is known as the: A. estimate of sample standard deviation. B. primed estimate of population standard deviation C. pooled estimate of population variance D. pooled estimate of degrees of freedom

C. pooled estimate of population variance

An sample size increases, the standard error: A. Also increases B. Decreases C. Stays constant D. Cannot be determined.

C. stays constant

The power of a statistical test is the probability of: A. Rejecting a true null hypothesis. B. Supporting a true null hypothesis. C. Rejecting a false null hypothesis D. Supporting a false null hypothesis.

C?

On an exam, in a cognitive psychology class most students attained a perfect score. This is an example of A. Ceiling effect B. Floor effect C. Symmetrical distribution D. Bimodal distribution

Ceiling effect

Place the 4 steps for computing the correlation coefficient into correct order 1. Add up the cross products of z scores 2. Change all scores to z scores 3. Divide by the numbers of people in the study 4. Figure cross product of z scores for each people

Change all scores to z scores, figure cross product of z scores for each people, add up the cross products of z scores, divide by the numbers of people in the study.

In an ANOVA, the between group variance is 30 and the within groups variance is 25. WHat is the f ratio? A. 5.00 B. 0.17 C. 0.83 D. 1.20

D. 1.20

Suppose you were conducting an ANOVA with 4 groups of five participants each. what are ur within groups and between group degree of freedom? A. 16;4 B. 12;3 C. 20;3 D. 16;3

D. 16;3

Suppose you were conducting ANOVA with 6 groups 10 participants each. What are the between groups and within groups degree of freedom respectively? A. 6;60 B. 60;6 C. 54;6 D. 5;54

D. 5;54

When using the f ration, one must pay attention to what? A. Significant level B. between group degree of freedom C. within group degree of freedom D. all of the above

D. All of the above

When a distribution is negative skewed, likely A. There are more scores piled up at the lo end of the range B. Floor effect C. Distribution approximately normal and symmetrical D. Ceiling effect

D. Ceiling effect

Which of the following is NOT an example of a nominal variable? A. Religious affiliation B. Social security C. Hair color D. Score on an IQ test.

D. Score on an IQ test.

If the difference between scores of 3 and 4 is approximately the same as the difference between scores of 15 and 16, this type of variable is known as A. nondirectional B. rank-order C. Differential D. equal interval

D. equal interval

Other names for the t-test for dependent means include all of the following except: A. Paired -sample t-test. B. t-test for matched samples. C. t-test for matched pairs. D. Independent samples t-test.

D. independent samples t-test

When estimating the variance of a population from a sample, you cannot use the variance of the sample directly because: A. it is based on absolute deviations. B. it is based on using squared deviations. C. it tends to be slightly large. D. it tends to be slightly small.

D. it tends to be slightly small

When using a t-table, the degree of freedom you should use for a t-test for independent means is the A. degree of freedom for Sample 1 divided by total degrees of freedom for both samples. B. average of the degrees of freedom for the two samples. C. sum of the two sample sizes minus one. D. sum of the two samples degree of freedom.

D. sum of two samples degree of freedom.

Setting the significance level cutoff at 0.10. Instead of the more usual 0.05. Increase the likelihood of: A. Failing to reject the null hypothesis B. Accepting the null hypothesis when, in fact, it is false. C. Type I error. D. Type II error.

D. type II error

In a class in which everyone is exactly 24 years old, the variance would be A. exactly 0 B. impossible to determine without information C. Approximately 1 D. Between 0 and 1

Exactly 0

You determine the characteristics of the comparison distribution (e.g. the normal distribution in the practice lectures) to answer which of the following questions? A. Given a particular sample value, what is the probability of obtaining that value if the research hypothesis is true? B. Given a particular population value, which is the probability of obtaining that value if the null hypothesis is false? C. Given a particular sample value, what is the probability of obtaining that value if the null hypothesis is true? D. Given a particular population value, what is the probability of obtaining that value if the research hypothesis is true?

Given a particular population value, which is the probability of obtaining that value if the research hypothesis Is true?

A study found that abseeism from work had a negative linear correlation with job satisfaction. This means A. Level of jobs satisfaction unrelated to absenteeism B. Lower the level of job satisfaction the higher the level of absent. C. Lower level of job satisfaction, lower level of absent.

Lower the level of job satisfaction, the higher the level of absent.

Roughly speaking, the standard deviation is the average amount that scores differ from A. Mean B. Histogram C. Range D. Median

Mean

When a distribution is positively skewed A. Mean and median are equal B. Mean and median are the same C. Median is greater than mean D. Mean greater than median

Mean greater than median

The _____ is the usual way of describing the representative value for nominal variable such as religious afflication A. Mode B. Mean C. Outlier D. Median

Mode

On the first exam in an introductory stats class, most students did very well, few did poorly. How would you describe distribution? A. Negative skewed B. Having floor effect C. Symmetrical D. Positive Skewed

Negative skewed

Several employees of a major corporation are rated for their degree of job satisfaction. If a particular employee's job satisfaction is rated 8 on a20-point scale, 8 represents that employee's A. Frequency B. Variable C. Score D. Percentile

Score

You are interested in relation btw of numbers of years working for a particular company and loneliness at work. You survey 50 workers at company and find a correlation coefficient of -.09. This considered A. Weak negative linear correlation B Weak positive linear correlation C. Strong negative linear correlation D. Strong positive linear correlation

Strong negative correlation

You conduct study in which you measure two political attitudes and find a correlation of +.70. This considered a A. Strong negative linear correlation B. Weak positive linear correlation C. Weak negative linear correlation D. Strong positive linear correlation

Strong positive linear correlation

Place the five steps for computing variance into correct order 1. Divide the sum of squared devations by the numbers of scores 2. Subtract mean from each score 3. Add up squared deviation score 4. Compute mean of sample 5. Square each of deviation scores

Subtract mean from each score, Add up squared deviation scores, Divide the sum of squared deviations by the numbers of score, Compute mean of sample, and then square each of the deviation scores.

In distribution with an even number of scores, the median will be the A. Most common value B. Average of two mid scores C. Median divided by mean D. Sum of scores divide by N-1

Sum of scores divided by N-1

Suppose the cutoff z-score on the comparison distribution is 1.64 and the sample value has a score of 1.32. Which of the following is true? A. The research hypothesis is rejected. B. The null hypothesis is rejected. C. The research hypothesis is supported. D. The null hypothesis cannot be rejected.

The null hypothesis cannot be rejected.

A research tests whether a new teaching method is more effective than the old one. What is the research hypothesis? A. The old teaching method is more effective than the new teaching method. B. The new teaching method is more effective than the old teaching method. C. There is some difference in effectiveness between the old teaching method and the new teaching method, but which is more effective is not predicted. D. There is no difference in effectiveness between the old teaching method and the new teaching method.

The old teaching method is more effective than the new teaching method.

A result is considered statistically significant when a sample value is so extreme that: A. The research hypothesis is rejected. B. The null hypothesis is rejected. C. The research hypothesis is accepted. D. The null hypothesis is accepted.

The research hypothesis is rejected.

The core logic of hypothesis testing involves figuring out the probability of getting a particular result if: A. The comparison distribution is true. B. The research hypothesis is true C. The sampling distribution is accurate. D. The null hypothesis is true.

The sampling distribution is accurate

What does it mean if a researched said she rejected the null hypothesis at the .05 alpha level? A. There was less than a 5% chance that she would have gotten such an extreme result by chance alone if the null hypothesis were true. B. There was more than a 5% chance that she would have gotten such an extreme result by chance alone if the null hypothesis were true. C. There is a 95% chance that the research hypothesis is true. D. There is a 5% chance that there is a difference between the two populations she is testing if the null hypothesis were true.

There is a 5% chance that there is a difference between the two populations she is testing if the null hypothesis were true.

A researcher tests whether there is any difference between how fast people work in the morning versus how fast they work in the evening. What is the null hypothesis? A. People who work at night work faster B. There is no difference in the speed at which people work. C. There is some difference, but which is faster is not predicted. D. People who work in the morning work faster.

There is no difference in the speed at which people work.

Unless there are ___ behavioral and social scientists generally use the mean as the measure of the rep value of groups of scores A. Z scores B. two modes C. histogram D. Outliers

Two modes

Suppose that a researcher wants to know if a new flu drug affects people, either by making them better or worse. Would this be a one-tail or two-tail test and why? A. One tailed, bc there is only one issue discussed- the drug. B. Two tailed, because there are two variables- whether or not people take the drug and how their flu is affected. C. One tailed, because there is only one interactions which is between the flu and the drug. D. Two tailed, because there is no predicted direction of the effect of the drug.

Two tailed, because there is no predicted direction of the effect of the drug.

A research wants to know if a new type of exercise improves peoples' health. Would this be a one-tailed or two tailed test and why? A. Two-tailed, because there is no predicted direction of difference. B. Two tailed, because they will have to study healthy and unhealthy people. C. One tailed, because the study only looks at the effects of exercise and does not take other factors into account. D. One tailed, because the study is only interested in whether the exercise health.

Two tailed, because they will have to study healthy and unhealthy people.

An intelligence test includes 15 items. Thus, a person could get any number correct between 0 and 15. Each of these numbers correct (0-15) that a person could possibly get is called A. frequency B. Mean C. Variable D. Value

Value

How do you set up a hypothesis testing problem? A. You set it up to test the opposite of what you predict will happen. B. You set it up test what you predict will happen. C. You set up a test that assumes the two populations are different, regardless of whether that is what you predict or not. D. You set up two problems, one to test what you predict and the other to test opposite.

You set it up test what you predict will happen.

WHen using the value of r^2 to calculate effect size for an anova. R^2 represents the proportion of total variance of scores from the __ that is accounted for by variation between the means of the groups. A. median of group 1 B, mode of group 2 and 3 C. grand mean D. protected t tests

c. Grand mean