Psych Stats 241 Exam #1

A Histogram is a __________ graph

Bar

A Polygon is a _________ graph

Line

Scores from a statistics exam are reported as deviation scores. Which of the following deviation scores indicates a higher position in the class distribution? a.) +8 b.) 0 c.) -8 d.) Cannot determine without more information

a.) +8

A sample consists of n=16 scores. How many of the scores are used to calculate the range? a.) 2 b.) 4 c.) 8 d.) All 16

a.) 2

For any set of data, the sum of the deviation scores will always be ____________. a.) Greater than 0 b.) Equal to 0 c.) Less than 0 d.) Impossible to determine without more information

a.) Greater than 0

Descriptive statistics are used to a.) Organize and summarize data b.) Make inferences about population based on sample data c.) Estimate causal relationships d.) Rule out extraneous variables

a.) Organize and summarize data

The variability of the scores in a sample tends to be ____________ the variability of the scores in the population from which the sample was obtained. a.) Smaller than b.) Larger than c.) Exactly the same as d.) Unrelated to

a.) Smaller than

A researcher conducts an experiment to determine whether moderate doses of St. Johns Wort have any effect of memory for college students. For this study, what is the independent variable? a.) The amount of St. Johns Wort given to each participant b.) The memory score for each participant c.) The group of college students c.) Cannot answer without more information

a.) The amount of St. Johns Wort given to each participant

A population of scores has ù= 50 and ó= 10. If 5 points are added to every score in the population, then the new mean and standard deviation would be ____________. a.) ù= 50 and ó= 10 b.) ù= 55 and ó= 10 c.) ù= 50 and ó+ 15 d.) ù= 55 and ó= 15

b

A researcher wants to examine the relationship between sleeping habits and grade point average for college students. A group of 100 students and each student is asked to report the average number of hours he/she sleeps each night and his/her grade point average. What research method is being used in this study? a.) Experimental Method b.) Correlational Method c.) Non-Experimental Method Comparing 2 Groups d.) None of the above

b.) Correlational Method

We use the correlational method a.) If we want to know whether one variable causes the other b.) If we want to know whether there is an association between variables c.) If we want to make inferences about the sample from population data d.) If we want to exclude extraneous variables

b.) If we want to know whether there is an association between variables

Using letter grades (A, B, C, D, and E) to classify student performance on an exam is an example of measurement on a(n) _______________ scale of measurement a.) Nominal b.) Ordinal c.) Interval d.) Ratio

b.) Ordinal

A researcher is interested in the sleeping habits of American college students. A group of 50 students is interviewed and the researcher finds that these students sleep an average of 6.7 hours per day. For this study, the average of 6.7 hours is an example of a(m) ____________. a.) Parameter b.) Statistic c.) Population d.) Sample

b.) Statistic

A researcher weighs each individual in a sample of 25 laboratory rats and calculates the average weight for the group. The average weight is an example of a _____________. a.) Parameter b.) Statistic c.) Variable d.) Constant

b.) Statistic

What additional information is obtained by measuring on an ordinal scale compared to a nominal scale? a.) Whether the measurements are the same or different b.) The direction of the differences c.) The size of the differences d.) None of the above

b.) The direction of the differences

In a study evaluating the effectiveness of a new medication designed to control high blood pressure, one sample of individuals is given the medicine and a second sample is given an inactive placebo. Blood pressure is measured for each individual. For this study, what is the dependent variable? a.) The medication b.) The placebo c.) Blood Pressure d.) The individuals given the medication

c.) Blood Pressure

The body of a nominal distribution indicates a.) The typical scores b.) The most frequent scores c.) Both a and b d.) None of the above

c.) Both a and b

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 different 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

A recent study reports that infant rats fed a special protein-enriched diet reached an adult weight 10% greater than litter-mates raised on a regular diet. For this study, what is the independent variable? a.) The rats given the protein-enriched diet b.) The rats given the regular diet c.) The type of diet given to the rats d.) The adult weight of the rats

c.) The type of diet given to the rats

A population of score has ù= 50 and ò= 10. If every score in the population is multiplied by 2, then the new mean and standard deviation would be ______________. a.) ù= 50 and ó= 10 b.) ù= 100 and ò= 10 c.) ù= 50 and ó= 20 d.) ù= 100 and ó= 20

d

In a correlational study a.) 1 variable is measured and 2 groups are compared b.) 2 variables are measured and 2 groups compared c.) 1 variable is measured and there is only 1 group of participants d.) 2 variables are measured and there is only 1 group of participants

d.) 2 variables are measured and there is only 1 group of participants

A population of N=6 has EX= 48. What is the population mean? a.) 288 b.) 48 c.) 12 d.) 8

d.) 8

Which of the following is not a continuous variable? a.) Time to solve a problem b.) Temperature c.) Height d.) Number of children in a family

d.) Number of children in a family

The implication of sampling error is a.) Samples are never identical to the population from which they came b.) Samples should never be used to make inferences about the population c.) No 2 samples are identical d.) Both A and B e.) Both A and C

e.) Both A and C