Statistics for psychology Chapter 2
A social psychologist gave survey to 8 active members of a small political action group about how many hours they put into the group's activities each week. The results were as follows: 12, 24, 30, 33, 40, 41, 41, and 44. Complete the mean, variance, and standard deviation.
M=34, SS=576, SD^2=72, SD=8.49
What is the median of at the scores 0, 0, 0, 2, 5, 6, and 8? A) 0 B) 2 C) 2.5 D) 3
Answer: B) 2
When ________ are summed,theresult will always equal zero
Answer: deviations scores
The Standard deviation for the scores 1, 7, and 13 is______
Answer: 4.90
based on the scores 1, 2, 3, 4, 5, 6, 6, 8, 8. 8, 9, and 10 a score of 6 is the A) mean B) median C) mode D) standard deviation
Answer: B) median
Based on the scores 1, 9, 3, 6, 1, 2 ,6, 2, 2, and 8 a score of 4 is the: A) mode, B) median C) mean D) standard deviation
Answer: C, mean
The general name for the representative value of a group of scores is?_______
Answer: Central Tendency
The mode of the following scores 3, 4, 6, 7, 10, 10, and 30 is A) 3 B) 7 C) 8.5 D) 10
Answer: D) 10
if the standard deviation is 4, the variance is A) 2 B) 4 C) 8 D) 16
Answer: D) 16
Readers of research articles my expect to find the mean reported in A) text B) A table C) a graph D) any of the above
Answer: D) any of the above
A measure of central tendency that is not very affected by outliers is the________
Answer: median; mode
A concierge is interested in how long it takes to bring passengers to the airport and then return to the hotel. The round-trip travel times for six taxi drivers were 45, 30, 42, 45, 41, and 43 minutes. A) Compute the mean, median and mode B) Based on the measures of central tendency, what can you infer about the distribution? C) Compute the variance and standard deviation
A) Mean=41, Median=42.5, Mode=45 B)The distribution is negatively skewed C) SS=158, SD^2=26.33, SD=5.13
the mean of the scores 2, 2, 2, and 6 is ?_______
Answer : 3
Based on the scores 1, 9, 3, 6, 1, 2, 6, 2, 2, and 8, a score of 2 is the: A) mode B) median C) mean D) standard deviation
Answer : A, mode
the formula for the standard deviation used in this chapter is A) 𝑆𝐷² B) 𝑆𝐷 C) √𝑆𝐷² D) ∑(𝜲-𝜧)²
Answer :C) √𝑆𝐷²
The variance of the scores 1, 4, and 7 is A) 3 B) 4 C) 6 D) 9
Answer C) 6
Based on the scores 1, 2, 3, 4, 5, 6, 6, 8, 8, 8, 9 and 10, a score of 8 is the A) mean B) median C) mode D) Standard deviation
Answer C) Mode
The median of the scores 6, 18, 4, 21, and 22 is_______
Answer: 18
In the group of scores of 2, 81, 82,82, and 84, the outlier is_________
Answer: 2
The variance for the scores 1, 7, and 13 is______
Answer: 24
𝜨 of the scores 6, 7, 7, and 8 is_______
Answer: 4
The mode of the scores of 1, 2, 4, 4, 4, 6, 7, 8, 8, 9, and 10 is A) 4 B) 5.7 C) 6 D) 8
Answer: A) 4
The symbol for the variance used in this chapter is A) 𝑆𝐷² B) 𝑆𝐷 C) √𝑆𝐷² D) ∑(𝜲-𝜧)²
Answer: A) 𝑆𝐷²
The variance is figured by dividing the sum of squared deviations by A) 𝜨 B) the mean C) the standard deviation D) the average 𝜡 score
Answer: A) 𝜨
If a cognitive psychologist finds that a group of one year old children can name 3, 3, 3, 4, 4, 5, 6, 7, 8, 9, 10, and 35 things the most useful measure of central tendency will be A) mean B) median C) mode D) range
Answer: B
The variance of the scores 0, 1, 1, and 2 is A) .25 B) .5 C) √.5 D) 1
Answer: B) .5
The standard deviation of the scores: 2, 0, 1, 8, and 4 is A) .067 B) 2.83 C) 3 D) 8
Answer: B) 2.83
The sample of four people, Person A had a score of 5 points below the mean, Person B has a score 3 points above the mean, and Person C has a score of 2 points above the mean. Which of the following provides the most accurate description of the score for Person D? A) It is equal to 0 B) It is equal to the mean C) It is below mean D) It is above the mean
Answer: B) It is equal to the mean
In statistical formulas, 𝜨 stands for A) the number of different values for a variable B) the number of scores C) the normal curve D) the normalized 𝜡 score
Answer: B) the number of scores
The ordinary average of a group of numbers is the: A) median B) mean C) standard deviation D)mode
Answer: B, mean
if the variance is 9, than the standard variance is A) 18 B) 81 C) 3 D) 4.5
Answer: C) 3
The median of the scores 1. 2. 4, 4, 4, 6, 7, 8, 8, 9, and 10 is A) 4 B) 5.7 C) 6 D) 8
Answer: C) 6
In a sample of three people, the first person has a score of 5 points above the mean, and the second has a score of 3 points above the mean. Which of the following provides the most accurate description of the score for the third person? A) It is below the mean B) It is below the mean by 4 points C) It is below the mean by 8 Points D) It cannot be described based on the information provided.
Answer: C) It is below the mean by 8 Points
The mean and the mode for a statistics test will be the same if the distributions is A) skewed B) normal C) bimodal D) median
Answer: C) Normal
Which statement is true for the scores of 1, 2, 3, 4, 5, 5, 7, 8, 9, and 10? A) the mode is greater than the median B) the median is greater than the mean C) the mean is greater than the median D) the mean is less than the mode
Answer: C) The mean is greater than the median
When describing a nominal variable, the best measure of central tendency to use is the A) mean B) median C) mode D) standard deviation
Answer: C) mode
When a distribution is skewed to the right A) the median is greater than the mean B) the mean and the median are the same C) the mean is greater than the median D) the mean and the median are equal
Answer: C) the mean is greater than the median
A psychologist studying cultural diversity who conducts a few lengthly interviews with members of various cultural communities is using: A) Behavioral techniques B) quantitative techniques C) qualitative techniques D) positivistic techniques
Answer: C)C) qualitative techniques
The 𝝨𝜲 for the scores 1, 1, 8, and 10 is A) 4 B) 4.5 C) 5 D) 20
Answer: D) 20
A psychologist conducts a survey of a job satisfaction among laborers and white-collar workers using a rating scale on which 1 indicates low satisfaction and 10 indicates high satisfaction. The findings are that laborers have a mean job satisfaction score of 4 and a variance of 1; white-collar workers have mean job satisfaction score of 7 and a variance of 10. Which statement most completely describes the meaning of these numbers? A) White-collar workers are more satisfied then laborers . B) White-collar workers and laborers a about equally satisfied. C)Laborers generally are less satisfied than white-collar workers, but laborers are just as likely to be highly satisfied as white collar workers are to be highly dissatisfied. D) Laborers are less satisfied than white-collar workers, and most laborers are about equally dissatisfied, while there is more variation in the satisfaction of white-collar workers.
Answer: D) Laborers are less satisfied than white-collar workers, and most laborers are about equally dissatisfied, while there is more variation in the satisfaction of white-collar workers.
the median is greater than the mean in a distribution that is A) symmetrical B) Skewed to the right C) normal D) skewed to the left
Answer: D) Skewed to the left
The correct description of the mean is: A) the sum of the scores that is most frequent in a distribution. B) the middle score of all the scores are ordered from lowest to highest. C) the average of the squared deviations from the median. D) the sum of the scores divided by the number of scores
Answer: D) The sum of the scores divided by the number of scores
The middle value in a set of scores arranged from lowest to highest is the A) mean B) mode C) average D) median
Answer: D) median
Which statement is true for the scores of 1, 2, 3, 4, 5, 5, 7, 8, 9, and 10? A) The mean is less than the median B) the mean is less than the mode C)the median and mode are both greater then the mean D) the median and the mode are the same
Answer: D) the median and the mode are the same
𝑆𝑆 refers to A) 𝑆𝐷² B) Variance computed using the 𝜨-1 formula C) standard deviation D) ∑(𝜲-𝜧)²
Answer: D) ∑(𝜲-𝜧)²
A deviation score is the difference between the score and the __________
Answer: Mean
𝝨𝜲/𝜨 is the formula of the?_______
Answer: Mean
if all the scores are ranked from lowest to highest, the median is the_______
Answer: Middle score (or middle scores, when there is an even number of scores)
The___________is the usual way of describing the central tendency of a nominal variable
Answer: Mode
The _______ is, approximately, the average that a score differs from the mean
Answer: Standard deviation
A mathematically equivalent version of a definitional formula that is easier to use when working by the hand with many scores is a(n) ___________
Answer: computational formula
A psychologist studying the rate at which infants in three different countries vocalized distress obtained the scores below from each country. Which group of infants showed the highest mean rate of distress vocalization? Country A) 9, 9, 10, 13, 8, 8, 11, 11, 10, 7 Country B) 15. 15, 16, 9, 14, 14, 17, 17, 16, 13 Country C 4, 6, 20, 17, 15, 21, 18, 18, 25, 2 A) country A B) country B C) country C D) Countries B and C were equally high
Answer: countries B and C were equally high Answer : D
Behaviorists such as B. F. Skinner sometimes objected to the use of statistics in psychology research because averages can distort the pattern of information revealed from observing the behavior of __________
Answer: each individual case
The value with the most scores is the_______
Answer: mode
A score with an extremely high or low value (relative to other scores in the distribution) is a(n)_______
Answer: outlier
The mean, median, and the mode will be the same when the distribution is _______
Answer: perfectly symmetrical and unimodal
the standard deviation is ______ the variance.
Answer: square root of
The variance of a group of scores is the average of the_____
Answer: squared deviations from the mean; squared deviations
The greek letter that means "add up all the scores that follow" is_______
Answer: ∑
the symbol used in the textbook for the variance of the group of scores is________
Answer: 𝑆𝐷²
Another way of symbolizing ∑(𝜲-𝜧)² is _________
Answer: 𝑆𝑆
In the symbols, deviation score is ______
Answer: 𝜲-𝜧
Explain what each of the three most widely used measures of central tendency indicate to a psychological researcher.
Arithmetic Mean, Median, & Mode. The Mean (or average) of the data collected from a group then calculated to get the Standard Deviation, the Median is the middle score of a group of scores after you have put them in order of magnitude. The Mode is the most frequent occurring score or outcome.
How might psychologists combine quantitative and qualitative methodologies to improve psychological research?
In an ideal social marketing program, researchers use both quantitative and qualitative data to provide a more complete picture of the issue being addressed, the target audience and the effectiveness of the program itself. They combined the qualitative data ( focus groups & in depth interviews) with quantitative data( "objective" survey questionnaires and statistical analyses)
Explain why the standard deviation is a better representation of variability
It is the most used variability measure. It is the solution to our square root problem
The scores of five high-school English teachers on a grammar test were 17, 19, 14, 20, and 20. Complete the mean, variance, and standard deviation.
M=18, SS=26, SD^2=5.2, SD=2.28
A psychologist interested in people's response to art had seven people indicate their liking for a particular piece of Egyptian sculpture; their ratings were 2, 4, 4, 5, 6, 7, and 7. Complete the mean, variance, and standard deviation.
M=5, SS=20, SD^2=2.86, SD=1.69
Based on company personnel records, a psychologist reports that, "During the last year, the mean number of sick days taken by shop employees was 7.3, with a standard deviation of 6.1." Explain what this result means to a person who has never had a course in statistics.
The mean 7.3 is the result of an average that was taken from set of data are added together and divided by the number of values (N). 6.1 is the result of The standard deviation which is the measure which tells us how scores are spread around the mean of the sample. In-other-words how much the scores "deviate" from the mean. The smaller the standard deviation, the closer together the values in the set are. A larger standard deviation shows that the values are more spread out from the mean.
A survey was conducted at a college to determine the number of hours students spent outside on weekends during the winter. For students from cold weather climates, the results were M=8, SD=1.5. For students from warm-weather climates, the results were M=5, SD=4.2. Explain what these numbers mean to a person who has never had a course in statistics, and suggest conclusions the person can draw from these results.
These numbers mean that the students from warm-weather climates spend more time outside on weekends during the winter than students from cold weather climates.
The variance is the same as the A) average of the squared deviations B) sum of the squared deviations C) average of he absolute deviations D) sum of the absolute deviations
Answer: A) average of the squared deviations
In a symmetrical distributions with a mean of 15, the median would be A) equal to 15 B) less than 15 C) greater than 15 D) either B or C
Answer: A) equal to 15
The correct formal for the mean is: A) 𝜧 = 𝝨𝜲/𝜨 B) 𝜧 = 𝝨𝜲²/𝜨 C) 𝜧 = (𝝨𝜲)²/𝜨 D) 𝜧 = 𝝨(𝜲-𝜧)²/𝜨
Answer: A 𝜧 = 𝝨𝜲/𝜨
The most common single value in a group of scores is the A) mode B) mean C) median D) average
Answer: A) Mode
Distribution is negatively skewed. The measures of central tendency are most likely to be in this order A) mean = 30, median = 50, mode = 70 B) mean = 30, median = 70, mode = 50 C) mean = 50, median = 50. mode = 50 D) mean = 70 median = 50, mode = 30
Answer: A) mean = 30, median = 50, mode = 70
Explain why the median is sometimes a better representation of the central tendency and then the mean
The mean is not robust, not tough to outliers( are the data that most people don't answer), the outliers effect the data or answer. But the median is robust or tough against outliers. The outliers won't effect the data.