WSU Psych 311 Exam 1 & 2
2. Suppose that the probability that any child of alcoholic parents becomes alcoholic is p = .16. Assuming independent outcomes, the probability that two children of alcoholic parents will be alcoholic equals A) .03 B) .32 C) .16 D) .25
A) .03
20. The probability of making zero to two errors per 1,000 keystrokes is 0.43, and the probability of making three to five errors per 1,000 keystrokes is 0.28. Find the probability (per 1,000 keystrokes) associated with making at most two errors. A) .43 B) .71 C) .29 D) .57
A) .43
5. A therapist goes through her records and finds that 200 of her 400 patients showed significant improvement in mental health over the past year. Hence, the probability of her patients showing significant improvement in mental health is A) .50 B) 400 C) .05 D) 200
A) .50
19. The probability of making zero to two errors per 1,000 keystrokes is 0.43, and the probability of making three to five errors per 1,000 keystrokes is 0.28. Find the probability (per 1,000 keystrokes) associated with making at least three errors. A) .57 B) .71 C) .43 D) .29
A) .57
8. In a game, the probability of winning money is p = .16, the probability of losing money is p = .54, and the probability of breaking even is p = .30. What is the probability of winning or losing money in this game? A) .70 B) 1.00 C) .54 D) .16
A) .70
17. The probability of making zero to two errors per 1,000 keystrokes is 0.43, and the probability of making three to five errors per 1,000 keystrokes is 0.28. Find the probability (per 1,000 keystrokes) associated with making at most five errors. A) .71 B) .57 C) .29 D) .43
A) .71
1. A news poll showed that voters had no preference for any of the three candidates. In this example, the probability of a vote for, say, Candidate A equals A) 1/3 B) 1/2 C) 2/3 D) 1.00
A) 1/3
19. A researcher finds that 12% of participants make between 3-5 visits to a physician each year. What are the real limits for this interval? A) 2.5-5.5 B) equal to the sum of the products for the previous interval C) 3-5 D) 2.5-3.5
A) 2.5-5.5
47. A researcher selects a sample of 100 participants from a population with a mean of 38 and a standard deviation of 20. About 68% of the sample means in this sampling distribution should be between a sample mean of A) 36 and 40 B) 34 and 40 C) 34 and 38 D) 38 and 44
A) 36 and 40
11. A researcher determines that the probability of missing class among students at a local school is p = .16. Assuming that the school has 300 students enrolled, how many students can we expect to miss class on a given day? Hint: This is a binomial probability distribution. A) 48 students B) 16 students C) 252 students D) There is not enough information to answer this question.
A) 48 students
34. A normal distribution has a mean equal to 53. What is the standard deviation of this normal distribution if 2.5% of the proportion under the curve lies to the right of x = 66.72? (Round your answer to two decimal places) A) 7.00 B) -7.00 C) 49.00 D) 0.14
A) 7.00
34. A researcher records the following data: 4, 4, 4, 4, and 3. How would you describe the variability of these data? A) It is very small (close to 0) because scores are approximately the same. B) It is equal to zero because scores are approximately the same. C) It is very large (much greater than 0) because 3 is an outlier in the data. D) It is negative because 3 is less than the other scores in the distribution.
A) It is very small (close to 0) because scores are approximately the same.
7. Which of the following is NOT a characteristic of probability? A) Probability is most useful for describing fixed events. B) Probability can be stated as a fraction or decimal. C) Probability varies between 0 and 1. D) Probability can never be negative.
A) Probability is most useful for describing fixed events.
40. A researcher selects two samples of 64 participants each. In the first sample the population mean was 10 and the variance was 16. In this second sample, the population mean was 25 and the variance was 9. Which sample will be associated with a larger standard error of the mean? A) Sample 1 B) Sample 2 C) None, both samples will have the same value for standard error D) There is not enough information to answer this question.
A) Sample 1
38. A researcher measures the number of trials it takes two samples of participants to master a new task. In both samples, SS = 240. Sample A consisted of 12 participants and Sample B consisted of 18 participants. Which sample is associated with the largest variance? A) Sample A B) Sample B C) Both samples have the same variance. D) There is not enough information to answer this question.
A) Sample A
51. What is the description of SS (Sum of squares) in words? That is, what does it stand for? A) Sum of squared deviations of scores from the mean. B) Sum of the squared scores divided by the mean. C) Sum or deviations of scores from the mean. D) Sum of the square roots of scores.
A) Sum of squared deviations of scores from the mean.
15. State the problem with this simple frequency distribution. Intervals Frequency 8-10 4 6-8 7 4-6 3 2-4 6 0-2 9 A) The class intervals overlap. B) The number of intervals is too small. C) The interval width is unequal. D) The interval width is too small.
A) The class intervals overlap.
30. 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. A) The two areas are the same. B) The first area is bigger. C) The second area is bigger.
A) The two areas are the same.
31. Which of the following will decrease the value of the mean? A) adding a score below the mean B) adding a score exactly equal to the mean C) deleting a score below the mean D) none of the above
A) adding a score below the mean
46. The mean of the sampling distribution of sample means is A) equal to the population mean B) equal to the population variance C) both A and B D) none of the above
A) equal to the population mean
21. In the stem-and-leaf display, each number to the right of the vertical line is referred to as a ________; the numbers to the left of the vertical line are called the ________. A) leaf; stem B) place; digit C) stem; leaf D) digit; place
A) leaf; stem
9. A researcher compares the amount of college debt (in dollars) that undergraduate students incur up to their four-year degree. College debt is on what scale of measurement? A) ratio B) nominal C) ordinal D) interval
A) ratio
8. A researcher records the time it takes to complete a memory task in a sample of 25 participants. He finds that the average participant completed the test in 43 seconds. The average time to complete this task is called a(n) A) sample statistic B) inferential statistic C) time trial D) population parameter
A) sample statistic
28. A researcher records 52 scores. What is the median position of these scores? A) the average of the 26th and 27th scores in numeric order B) the 27th score in numeric order C) the 26th score in numeric order D) It's not possible to know this without the raw scores.
A) the average of the 26th and 27th scores in numeric order
10. Which of the following best describes an independent variable? A) the manipulated variable B) the population variable C) the measured behavior D) the sample variable
A) the manipulated variable
13. Which of the following best describes a dependent variable? A) the measured behavior B) the manipulated variable C) the population variable D) the sample variable
A) the measured behavior
12. Each of the following is an example of a binomial distribution, except A) the time it takes to complete a driving test B) the number of votes for or against a candidate C) the number of heads in ten flips of a fair coin D) the number of males and females in a sample
A) the time it takes to complete a driving test
22. The normal distribution has all of the following characteristics, except A) the total area under the curve is greater than 1.0 B) the mean, median, and mode are equal C) it is mathematically defined D) the mean can be any number
A) the total area under the curve is greater than 1.0
40. Each deviation in the numerator for variance is squared because A) without squaring each deviation, the solution for SS would be zero B) this inflates the value for variance, making it more accurate C) without squaring each deviation, the solution could be negative D) both A and C
A) without squaring each deviation, the solution for SS would be zero
6. A researcher records the following data for the number of bids made on a sample of items sold at an auction. Based on the table, what was the probability that an item had 7 bids made on it? Number of Bids Frequencies 3 5 4 12 5 7 6 6 7 10 A) .10 B) .25 C) 10 D) 5
B) .25
36. A researcher decides to split scores on an exam into quartiles. She determines that a score of 64 is at the 25th percentile, a score of 74 is at the 50th percentile, and a score of 80 is at the 75th percentile. What is the interquartile range (IQR) for these data? A) 6 B) 16 C) 10 D) There is not enough information to answer this question.
B) 16
22. The following is a simple frequency distribution table. If we convert this frequency distribution to relative percentages, which of the following gives the corresponding percentages in each interval listed from the top down. Intervals Frequency 44-46 6 41-43 4 38-40 5 35-37 10 32-34 5 30 A) 6, 10, 15, 25, 30 B) 20%, 13%, 17%, 33%, 17% C) 20%, 33%, 50%, 67%, 100% D) 0.2, 0.13, 0.17, 0.33, 0.17
B) 20%, 13%, 17%, 33%, 17%
50. How many possible samples of size 2 can be selected from a population of 5 using theoretical sampling? A) 32 B) 25 C) 5 D) 10
B) 25
13. If the standard deviation of a probability distribution is 9, then the variance is A) 9 B) 81 C) unknown D) 3
B) 81
43. A researcher records the sound (in decibels) during a series of lessons taught by a substitute teacher at a local elementary school. In his study, he found that the sound was 80±6 (M±SD) decibels. Assuming the data are normally distributed, which of the following is an appropriate conclusion? A) 5% of classes were louder than 68 decibels. B) 95% of classes were between 68 and 92 decibels. C) 68% of classes were between 68 and 80 decibels. D) all of the above
B) 95% of classes were between 68 and 92 decibels.
45. What does it mean to say that the sample mean is an unbiased estimator of the population mean? A) The sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population. B) If we select a sample at random, then on average we can expect the sample mean to equal the population mean. C) The sample means will vary minimally from the population mean. D) all of the above
B) If we select a sample at random, then on average we can expect the sample mean to equal the population mean.
23. The size of a population is symbolized as ________, whereas the size of a sample is symbolized as ________. A) M; B) N; n C) ; M D) n; N
B) N; n
24. A researcher reports that "the average shopper in the sample (n = 12) purchased $65.00 worth of items ( = $65.00) during a busy shopping day." What mistake was made is this citation? A) None; this citation is written appropriately. B) The sample mean is written using the wrong notation. C) The sample size is written using the wrong notation. D) both B and C
B) The sample mean is written using the wrong notation.
30. A professor grades 120 research papers and reports that the average score was an 80%. What do we know about the sum of the differences of these 120 scores from their mean of 80%? A) The sum of the differences is 80%, the same as the mean. B) The sum of the differences is equal to zero. C) The sum of the differences is minimal. D) It is impossible to know without knowing each of the 120 scores.
B) The sum of the differences is equal to zero.
52. EXTRA CREDIT!! A researcher randomly selects a sample of athletes and reports that their average score on a health and fitness scale is 23. Based on the characteristics of the sample mean, what does this say about the mean in the population? A) It tells us that the mean in the population is no less than 23. B) We expect that the population mean is equal to 23 because the sample mean is an unbiased estimator of the population mean. C) There is no way to know without knowing the size of the sample. D) Nothing; it was just a sample.
B) We expect that the population mean is equal to 23 because the sample mean is an unbiased estimator of the population mean.
9. Which rule states that when two outcomes are independent, the probability that these outcomes occur together is the product of their individual probabilities? A) additive rule B) multiplicative rule C) both A and B D) none of the above
B) multiplicative rule
26. A researcher records the following data for the number of dreams recalled during a night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 0. Is the mean equal to the median in this example? A) No; the mean is larger than the median. B) Yes. C) No; the median is larger than the mean. D) There is not enough information to answer this question.
B) Yes.
17. A researcher wants to determine how many participants will take less than 24 seconds to complete a cognitive performance task. If he constructs a frequency distribution for these data, what type of distribution would be most appropriate to answer his question? A) a cumulative frequency distribution from the top down B) a cumulative frequency distribution from the bottom up C) a simple frequency distribution D) a relative frequency distribution
B) a cumulative frequency distribution from the bottom up
39. Suppose that a researcher selects a sample of participants from a population. If the shape of the distribution in this population is positively skewed, then what is the shape of the sampling distribution of sample means? A) approximately negatively skewed B) approximately normally distributed C) approximately positively skewed D) There is not enough information to answer this question, because the population mean and variance are not given.
B) approximately normally distributed
52. Qualitative data varies by ________; quantitative data varies by ________. A) value; level B) class; amount C) level; value D) amount; class
B) class; amount
14. When the probability of one outcome changes depending on the occurrence of a second outcome, these outcomes are referred to as A) independent B) conditional C) complementary D) mutually exclusive
B) conditional
12. The use of tables and graphs to summarize data is an example of A) generalization B) descriptive statistics C) inferential statistics D) interpretation
B) descriptive statistics
3. The scale of measurement a researcher uses A) must be able to measure continuous variables B) determines the type of inferential statistics that can be done C) depends on whether a sample or population is being studied. D) depends on whether the researcher wants to only report descriptive statistics or also report inferential statistics
B) determines the type of inferential statistics that can be done
5. A therapist observes that spouses are more likely to forgive their partners for lying to them if they find out the truth from their spouse and not a third party. In this example, the dependent variable is A) lying B) forgiveness C) the spouse D) the number of partners
B) forgiveness
38. A researcher selects a sample of 16 participants from a population with a variance of 4. What is the standard error of the mean? A) greater than 1 B) less than 1 C) equal to 1 D) There is not enough information to answer this question.
B) less than 1
26. The standard normal distribution is normally distributed with a mean of ____ and a variance of ____. A) any value; any positive value B) any positive value; any value C) 1; 0 D) 0; 1
D) 0; 1
21. The following distribution most closely approximates a A) negatively skewed distribution B) normal distribution C) multimodal distribution D) positively skewed distribution
B) normal distribution
6. Each of the following is an example of quantitative data, except A) age in years B) political affiliation C) weight in ounces D) income in dollars
B) political affiliation
42. What values are distributed along the x-axis for a sampling distribution of the sample mean? A) scores B) sample means C) sample variances D) both B and C
B) sample means
4. Researchers measure data in a ________ to learn more about individuals in the larger _______ of interest. A) inference; statistic B) sample; population C) statistic; inference D) population; sample
B) sample; population
41. For the experimental sampling strategy, A) participants are not sampled from the population, but instead are sampled from other samples already drawn B) sampling is without replacement C) the order in which a participant is selected matters D) sampling is with replacement
B) sampling is without replacement
24. An example of a binomial variable includes A) weight (in pounds) B) sex (male, female) C) time (in seconds) D) all of the above
B) sex (male, female)
50. A researcher records 17 scores. What is the median position of these scores? A) the average of the 8th and 9th scores in numeric order B) the 9th score in numeric order C) the average of the 9th and 10th scores in numeric order D) It's not possible to know this without the raw scores.
B) the 9th score in numeric order
14. Bar charts are a lot like histograms, except A) the bar chart summarizes continuous data B) the bars displayed in the graph do not touch C) the bar chart summarizes quantitative data D) all of the above
B) the bars displayed in the graph do not touch
36. Each of the following statements are true, except that A) increasing the sample size will decrease standard error B) the larger the sample size, the larger the standard error C) the larger the standard deviation in the population, the larger the standard error D) both B and C
B) the larger the sample size, the larger the standard error
3. Two outcomes are said to be mutually exclusive when A) the probability of the two outcomes occurring together sums to one B) the probability of the two outcomes occurring together is equal to zero (p = 0) C) the probability of the occurrence of one outcome has no effect on the probability of the occurrence of the second outcome D) the probability of the two outcomes occurring together is greater than zero (p > 0)
B) the probability of the two outcomes occurring together is equal to zero (p = 0)
11. You are interested in measuring the construct, reinforcement. Which of the following measures for this construct is quantitative and continuous? A) the rating of a reward on a scale from 1 (not reinforcing) to 7 (very reinforcing) B) the size of a reward in grams C) the number of rewards received D) the type of reward (food, money)
B) the size of a reward in grams
1. The "empirical rule" states that A) all scores will fall within 3 standard deviations of the mean. B) at least 68% of scores fall within 1 standard deviation of the mean. C) at least 95% of scores fall within 2 standard deviation of the mean. D) both b and c
Both B & C
29. What is the z score for scores in the bottom 5%? A) .4801 B) 1.645 C) -1.645 D) -0.050
C) -1.645
18. The probability of making zero to two errors per 1,000 keystrokes is 0.43, and the probability of making three to five errors per 1,000 keystrokes is 0.28. Find the probability (per 1,000 keystrokes) associated with making more than five errors. A) .43 B) .71 C) .29 D) .57
C) .29
37. A researcher records the time in seconds it takes a sample of participants to walk alone through a dark portion of campus. The researcher computes SS = 1,000. Assuming that a sample of 11 participants was observed in this study, what is the standard deviation for these data? A) 1000 seconds B) 1 seconds C) 10 seconds D) 100 seconds
C) 10 seconds
44. A researcher selects a sample of size 4 from a population of size 6. How many possible samples of this size can be selected using experimental sampling? A) 4,096 B) 1,296 C) 15 D) 30
C) 15
2. When SS = 100 and N = 25, the population standard deviation is equal to __ A) 4 B) There is not enough information to determine the population standard deviation. C) 2 D) 10
C) 2
10. A researcher reports that the probability of a college student living on campus is p = .38. If a small local college has 2,000 students enrolled, then what is the standard deviation of college students living on campus? Hint: This is a binomial probability distribution. A) 760 students B) 471.2 students C) 21.7 students D) There is not enough information to answer this question.
C) 21.7 students
29. A researcher selects a sample of 6 males and 11 females. She asks participants to rate the likelihood they would do female-stereotyped jobs (such as nursing or school teaching) on a scale from 1 = not likely at all to 5 = very likely. Men indicated that they would be less likely to do these jobs (M = 2.1) compared with women (M = 4.3). What is the weighted mean for this entire sample of 17 participants? A) 3.2 B) 2.1 C) 3.5 D) 4.3
C) 3.5
20. What is the percentile point at the 80th percentile in the following distribution? Frequency Percentile Rank 9-11 100% 6-8 80% 3-5 40% 0-2 20% A) 6 B) 7 C) 8 D) 2
C) 8
16. Fill in the missing values for A and B in this frequency distribution table: Intervals Frequency 6.0-6.6 12 5.3-5.9 7 4.6-5.2 B 3.9-4.5 10 A-3.8 8 50 A) A = 3.1, B = 14 B) A = 3.3, B = 13 C) A = 3.2, B = 13 D) There is not enough information to complete this table.
C) A = 3.2, B = 13
51. EXTRA CREDIT!! What is the central limit theorem? A) It explains that if we select a sample at random, then on average we can expect the sample mean to equal the population mean. B) It explains that sample means will vary minimally from the population mean. C) It explains that a sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population. D) all of the above
C) It explains that a sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population.
33. What is the z score for scores in the top 2.5%? A) .0250 B) .0124 C) .675 D) 1.96
D) 1.96
31. Which proportion is largest in a z distribution? A) The proportion of area greater than z = 1.0. B) The proportion of area less than z = 0. C) The proportion of area between z = +1 and z = -1. D) The proportion of area above the mean.
C) The proportion of area between z = +1 and z = -1.
44. Which of the following is the best explanation for why the standard deviation is almost always reported with the mean? A) The standard deviation is also a measure of central tendency, so it is important to report this value with the mean. B) This is not true; the standard deviation is rarely reported with the mean. C) The standard deviation measures the spread of scores from the mean, so it is important to know both the mean and the standard deviation. D) The mean and standard deviation estimate basically the same thing, so these values are typically reported together.
C) The standard deviation measures the spread of scores from the mean, so it is important to know both the mean and the standard deviation.
45. What terms refer to each of the following measures, respectively: mean, median, and mode. A) most, average, and middle B) middle, most, and average C) average, middle, and most D) average, most, and middle
C) average, middle, and most
41. A researcher selects a sample of 24 participants and has them complete a survey on dating preferences. In this example, what are the degrees of freedom for sample variance and what does this figure represent? A) df = 24; dividing SS by df makes the sample variance an unbiased estimator of the population variance. B) df = 24; it represents the number of scores that are free to vary in a sample. C) df = 23; it represents the number of scores that are free to vary in a sample. D) df = 23; dividing SS by df makes the sample variance a biased estimator of the population variance.
C) df = 23; it represents the number of scores that are free to vary in a sample.
28. Another name for a binomial variable is a A) random variable B) participant variable C) dichotomous variable D) systematic variable
C) dichotomous variable
7. Procedures that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected best describes A) sample statistics B) population parameters C) inferential statistics D) descriptive statistics
C) inferential statistics
47. An education counselor records the number of high school graduates enrolled in community colleges, four-year colleges, and universities. What scale of measurement is the type of college? A) ratio B) interval C) nominal D) ordinal
C) nominal
15. The probability of a college student being employed is p = .35. The probability of a student being employed and dropping out of college is p = .20. Hence, the probability of a student dropping out of college, given that he or she is employed, is A) p = .55 B) p = .07 C) p = .57 D) There is not enough information to answer this question.
C) p = .57
43. What values are distributed along the x-axis for a sampling distribution of the sample variance? A) scores B) sample means C) sample variances D) both B and C
C) sample variances
25. The normal distribution is symmetrical, which means that A) this characteristic has no practical implication B) there are an infinite number of possible normal distributions C) scores above the mean are distributed the same as scores below the mean D) extreme scores are possible in a normal distribution
C) scores above the mean are distributed the same as scores below the mean
32. Scores far from the mean are located in the ________ of a normal distribution. A) most uncertain areas B) body C) tails D) most sensitive areas
C) tails
48. Increasing the number of observations or samples in a study will decrease the standard error (standard error of the mean). This is known as A) the law of diminishing returns B) the theoretical law of estimates C) the law of large numbers D) Bob (not the right answer)
C) the law of large numbers
27. The unit of measurement distributed along the x-axis of a standard normal distribution is referred to as a A) normalized deviation B) standardized score C) z score D) x-score
C) z score
49. Measures of variability can range in value from A) It depends on the value of the mean for a given distribution. B) It depends on whether the variability is positive or negative. C) - to + D) 0 to +
D) 0 to +
42. A researcher measures the amount of coffee consumed by college students while studying during the final exam week. In her study, she found that students drink 2.3±0.8 (M±SD) cups of coffee per study session. Assuming the data are normally distributed, which of the following is the most appropriate conclusion? A) Most students drink between 2.3 and 3.9 cups of coffee per study session. B) The average student drinks less than 2.3 cups of coffee per study session. C) Most students drink between 0.7 and 2.3 cups of coffee per study session. D) Most students drink between 1.5 and 3.1 cups of coffee per study session.
D) Most students drink between 1.5 and 3.1 cups of coffee per study session
39. Which of the following is true about the computational formula for variance? A) It is a short-cut method for calculating variance when the population or sample size is large. B) It is derived mathematically from the definitional formula. C) The computational formula will always produce the same solution as the definitional formula (give or take rounding errors). D) all of the above
D) all of the above
49. The sample variance is an unbiased estimator of the population variance A) when dividing SS by n B) when dividing SS by df C) when dividing SS by n - 1 D) both B and C
D) both B and C
16. Bayes' theorem is often applied to a variety of ________ probability situations, including those related to statistical inference. A) fixed B) generic C) absolute D) conditional
D) conditional
32. A researcher records the time (in seconds) that participants arrive late for a scheduled research study. Assuming these data are normally distributed, which measure of central tendency is most appropriate to describe these data? A) mode B) range C) median D) mean
D) mean
27. The ________ is the middle value in a distribution of scores that are listed in numeric order. A) mode B) mean C) range D) median
D) median
46. State the four scales of measurement in order from least informative to most informative. A) ordinal, nominal, ratio, interval B) nominal, ordinal, ratio, interval C) ordinal, nominal, interval, ratio D) nominal, ordinal, interval, ratio
D) nominal, ordinal, interval, ratio
18. A cumulative percentage summary that indicates the percentage of scores at or below a given value is called a A) cumulative frequency B) relative percentage C) relative frequency D) percentile rank
D) percentile rank
37. Regardless of the shape of the distribution in the population, the sampling distribution of sample variances approximates a A) negatively skewed distribution B) normal distribution C) multimodal distribution D) positively skewed distribution
D) positively skewed distribution
4. The proportion or fraction of times an outcome is likely to occur is referred to as A) a random event B) sample space C) luck D) probability
D) probability
48. To construct a pie chart, first distribute the data as A) cumulative frequencies B) cumulative percentages C) cumulative relative percentages D) relative percentages
D) relative percentages
33. A researcher asks participants to estimate the height (in inches) of a statue that was in a waiting area. The researcher records the following estimates: 40, 46, 30, 50, and 34. If the researcher removes the estimate of 40 (say, due to an experimenter error), then the value of the mean will____ (Hint: Calculate the mean first!) A) increase B) become negative C) decrease D) remain the same
D) remain the same
23. What is the implication for the tails of a normal distribution being asymptotic? A) that this characteristic has no practical implication B) that there are an infinite number of possible normal distributions C) that scores above the mean are distributed the same as scores below the mean D) that extreme scores are possible in a normal distribution
D) that extreme scores are possible in a normal distribution
35. Regardless of the number of scores in a distribution, the range only includes ___ score(s) in its calculation. A) the average B) at most two C) one D) two
D) two
35. How is the standard error of the mean typically reported in a graph? A) by listing group names along the x-axis B) it is never reported in a graph C) by plotting sample means D) using error bars
D) using error bars
25. When would a researcher calculate a population mean? A) when the sample mean it not available B) when it is not possible to measure all data in a population C) when data are measured for of a portion of individuals from a population D) when data are measured for all members of a population
D) when data are measured for all members of a population