Exam 1 Questions

If a constant is added to every score in the distribution, and the standard deviation will increase by that constant True or false

False

If score, X equals 30, has a percentile rank of 90%, then 90% of the scores in the distribution will have a value equal to30 True or false

False

The value obtain for SS depends on whether a group of scores is a sample or a population True or false

False

Sample scores: 8, 12, 9, 11, 6,10, 7 The (£x)2 for this distribution of scores is a) 64 b)3969 c) 595 d) 9

b) 3969

For a normal population with a mean of u = 80 and a standard deviation of 10 what is the probability of obtaining a sample mean greater than M equals 75 for a sample of n equals 25 scores? a) p=0.0062 b)p=0.9938 c) p=0.3085 d)p=0.6915

b) p=0.9938

In random samples, each with any calls nine scores, are selected from a normal population with u equals 80 and o equals 18, how much difference, on average, should there be between a sample mean in the population mean? a) two points b) six points c) 18 points d) cannot be determined without additional information

b) six points

If a mean is 86 and the standard deviation is 16 a raw score of 54 would be _____ Standard deviation's _____thethe mean and would have a Z score of _____ a) one, above, +2 b) two below -2 c)two above -2 d) there's not enough information to determine the answer

b) two below -2

The owner of a local restaurant wanted to determine if drawing :-) faces on the checks of lunch customers would increase tips for her wait staff. For the entire wait staff, the owner drew smiley faces on a random half of the lunch customers who ate at her restaurant. In this experiment, checks with :-) faces are a) independent variable b) A value of a variable c) The dependent variable d) A continuous variable

b) value of the variable

For a particular sample, the largest distance (deviation) between a score and the mean is 11 points. The smallest distance between a score and the mean is 4 points. Therefore the standard deviation, a) will be less than 4 b) will be between 4 and 11 c) will be greater than 11 d) it is impossible to say anything about the standard deviation

b) will be between 4 and 11

x:1,4,0,4,4,7 What is £X +1 a)20 b)21 c)26 d)27

b)21

A continuous distribution of scores is organized and a group of frequency distribution table with an interval with a five points. If the lowest scores in the distribution is X = 47 in the bottom interval in the table it should be. a) 40 - 45 b) 45-49 c)45-50 d)46-51

b)45-49

Brenda is trying to determine the lowest possible score she could've made on a statistics examination and still be in the top 75% of her class. The mean of the exam is 67 and the standard deviation is 3.25. What is the lowest possible score she could've made and still be in the top 75% of her class. a)64.82 b)69.18 c)73.23 d) 64.76

b)69.18

x:1,4,0,4,4,7 What is the range a)6 b)7 c)4 d) cannot be determined

b)7

Sample scores: 8, 12, 9, 11, 6,10, 7 The median for the distribution is a)0 b) 9 c)10 d)63

b)9

Size of McDonald's meal kids meal, regular, supersize a)nominal b)ordinal c)interval d) ratio

b)ordinal

According to the central limit theorem, the standard air for the sample mean approaches zero as the sample size approaches infinity True or false

True

The distribution used in the previous two questions is a sample. If it were a population, the standard deviation would be a larger value in the sample standard deviation valiant True or flase

True

The standard error for sample mean can never be greater than the standard deviation of the population from which the sample is selected True or false

True

Value for the standard deviation cannot be larger than the value for the range True or false

True

In a normal distribution, what's the score values separates the high is 40% of the scores and the rest of the distribution? a) Z equals 1.28 b) Z equals -1.28 c) Z equals .25 d) Z equals -.25

Z equals .25

Kiran's algebra teacher uses an absolute grading scale (A=95-100). On a recent exam, Kiran scored at the 17th percentile; therefore a) 17%, at most, scored lower than Kiran b)17%, at most, scored higher than Kiran c)83% scored the same as Kiran d)66% scored the same as Kiran

a) 17%, at most, scored lower than kiran

The owner of a local restaurant wanted to determine if drawing :-) faces on the checks of lunch customers would increase tips for her wait staff. For the entire wait staff, the owner drew smiley faces on a random half of the lunch customers who ate at her restaurant. The dependent variable in this experiment is a) The amount of tip money left by the customers b) Smiley face Checks and no :-) checks c) The number of wait staff d) it was not given

a) The amount of tip money left by the customers

In a negatively skewed distribution, measures of central tendency will have the following order a) mode, median mean b) mean, median, mode c) median = mode = mean d) mean, mode, median

a) mode, median mean

In a positively skewed distribution of exam scores, Tom scored at the mean, Mary scored at the medium, and Jane scored at the mode. Who had the highest score?

a)Tom b)Mary c)Jane d)more information needed

DSM diagnosis a)nominal b)ordinal c)interval d) ratio

a)nominal

A random sample of any quotes four scores is selected from a normally distributed population with u equals 80 and o equals 12. What is the probability that the sample mean will be greater than 86? a) 0.0228 b) 0.0668 c) 0.1587 d) 0.3085

c) 0.1587

Which set of scores has the smallest standard deviation? a) 11, 17, 31, 53 b) five, 11, 42, 22 c) 145, 143, 145, 147 d) 27, 105, 10, 80

c) 145, 143, 145, 147

In a population of N equals six, five of the individuals all have scores that are exactly 1 point above the mean. From this information you can determine that the score of the sixth individual must be a)One point above the mean b)One point below the mean c)Five points below the mean d)Five points above the mean e)Can't be determined

c) 5 points below the mean

A random sample of an equals 36 scores is selected from a population. Which of the following distributions definitely will be normal? a) The scores in the sample form a normal distribution b) The scores in the population will form a normal distribution c) The distribution of sample means will form a normal distribution d) neither the sample, the population, nor the distribution of sample means will definitely be normal

c) The distribution of sample means will form a normal distribution

All of the following are characteristics of the z scores distribution except a)The Z score distribution will always have a standard deviation of one b)The shape of the Z score distribution will be the same as the raw score distribution c)This sign of the Z score indicates how far the scores is from the mean d)Z score distribution will always have a mean of 0

c) The sign of the Z score indicates how far score is from the mean

The owner of a local restaurant wanted to determine if drawing :-) faces on the checks of lunch customers would increase tips for her wait staff. For the entire wait staff, the owner drew smiley faces on a random half of the lunch customers who ate at her restaurant. The independent variable in this experiment is a) a polyomous variable b) a continuous variable c) a dichotomous variable d) a confounding variable

c) a dichotomous variable

Which of the following is true for most distributions? a) around 30% of the scores will be located within One standard deviation of the mean. b) around 50% of the scores will be located within one standard deviation of the mean c) around 70% of the scores will be located within one standard deviation of the mean d) around 90% of the scores will be located within one standard deviation of the mean

c) around 70% of the scores will be located within one standard deviation of the mean

Time on o'clock a)nominal b)ordinal c)interval d) ratio

c) interval

x:1,4,0,4,4,7 What effect would taking out the score of seven have on the standard deviation? a) no change b) it would increase it c) it would decrease it d) cannot be determined

c) it would decrease it

The average verbal SAT score for the entire class of entering freshmen is 530. However, if you select a sample of 20 freshmen and compute their average verbal SAT score you probably will not get exactly 530. What statistical concept is used to explain the natural difference that exists between a sample mean and the corresponding population mean? a) statistical error b) inferential error c) sampling error d) parametric error

c) sampling error

What happens to the expected value of M as a sample size increases a)It also increases b)It decreases c)It stays constant d)The expected value does not change in a predictable manner one sample size increases

c) stays constant

If you have a score of x=75 on an exam, which set of parameters would give you the highest relative position in the class? a) u=70 o=5 b) u=70 o=10 c) u=60 o= 5 d) u=69 o=10

c) u=69 o=5

A sample of an equals 100 scores M equals 90 is selected from a population with u equals 80 and with a standard deviation of 20. On average how much air is expected between the sample mean and the population mean a).2 b).8 c)2 d)5

c)2

And introductory psychology class has nine freshman males, 15 freshman females, eight sophomore males, and 12 sophomore females. If one student is randomly selected from this class, what is the probability of getting a sophomore? a)8/24 b)20/24 c)20/44 d)14/44

c)20/44

x:1,4,0,4,4,7 How many scores would be used to calculate the standard deviation a)2 b)5 c)6

c)6

A sample of n equals 15 scores has a mean of eight. Another sample of scores has n =five and a mean of four. If these two sets of scores are combined, what is the mean for the total group a) 5 b)6 c)7 d)cannot be determined

c)7

The classrooms in economics department are numbered from 100 to 120. A professor records the number of classes held in each room during the fall semester. If the values are represented in a frequency distribution graph what kind of graph would be appropriate? a)Histogram b)Polygon c)Histogram or a polygon d)Bargraph

d) bargraph

Minutes passed since beginning this exam a)nominal b)ordinal c)interval d) ratio

d)ratio

Subjective units of joy you experience as you've completed this exam a)nominal b)ordinal c)interval d) ratio

d)ratio

_____ Will always equal zero a) the mean if the distribution of z scores b) the sum of the squared deviation scores c) the sun of the deviation scores d) A and B e) A and C f) All of the above

e) A and C

A recent report concludes that subjects given a diet containing oat brand had lower cholesterol levels than subjects on a similar diet without oat bran. For this study, cholesterol level is the dependent variable. a) true b) false

true