Intro to Measurements and Statistics - Essay Example

PSYC-2750 Mid-Term Exam Fall 2 Introduction to Measurements and Statistics For each of the following, indicate whether the data is measured on a nominal, ordinal, interval, or ratio scale. (5 points each)a) waist sizes of 65-year-old men – interval b) amount of alcohol in a can of Budweiser beer – nominal c) countries of origin of Webster students – nominal d) temperature in centigrade of Starbuck’s – ratio e) religions of Webster college – ordinal f) social class of Webster – ratio g) weights of 65-year-old women – interval h) IQ of Webster students – nominal i) scores on the CPA exam for Webster students – interval j) speeds of fastballs thrown by American League pitchers – ratio k) strength categories of hurricanes (1, 2, …, 5) – ordinal l) genders of Wal-Mart – nominal m) rank of college professors (Instructor, Assistant Professor, Associate Professor, Full Professor) – interval n) class standing of Webster students (Freshman, Sophomore, … ) – nominal (2)  For each of the following, indicate the appropriate measures of central tendency that may be used for analysis.

  List as many as are appropriate. (1 point each)a) For data measured on a nominal scale, you may use: mode b) For data measured on an ordinal scale, you may use: non-parametric analysis of variancec) For data measured on an interval scale, you may use: standard deviation(3) Identify the independent variable and dependent variable(s) in the following experiments. (.5 Each)a. A researcher was interested in the effects of rewards on motivation. Some students were told that they would be given a special award for reading the textbook.

Other students were simply asked to read the textbook. Later, the students were unobtrusively observed for how much time they spent reading the textbook. Answer: Independent variables (reading of the books) and dependent variable (motivation)b. The University of Alabama has the highest paid coaching staff in college football. They also have the best recruiters in college football. Researchers are attempting to identify why the Alabama has the best college football players. Answer: Independent variable (recruiters) and dependent variable (football players)c.

Researchers are interested in teaching styles. Some teachers are asked to learn and incorporate developmental learning strategies in their college level course work. Student outcomes from both regular classes as well as updated classes were examined. Answer: Independent variable (students’ outcome) and dependent variable (learning strategies)d. Subjects read about a woman who used a particular title, and then rated her on a number of traits. When the woman used the title Ms. rather than Miss or Mrs.

, she was assumed to be more assertive, achievement oriented, and dynamic, but also cold, unpopular, and unlikely to have a happy marriage.Answer: Independent variable (woman’s title) and dependent variable (trait)(4) In order to estimate the amount of TV watched by students, a researcher surveys a random sample of Webster students. All of the Webster students would be considered what? (1pt).(5) The following is a frequency distribution showing the amount of time it took a sample of employees to complete a certain job: (8pts) Number of Days (x) Frequency(f)F(x) 2 1020 41768 5 1890 7 12849  40360 10 330Total: 37100662(a) Calculate the mean= 6.

62 median= 1.0, mode 40, and range = 37. (6) Lets assume you are conducting an experiment to determine the effect of a new drug on the incidence of epileptic seizures. You select 20 epileptics from the 150 epileptics being treated at a nearby hospital and administer the drug to them. You record the number of seizures in each of the 20 subjects for one month. The new drug is an example of a(n)= 20(1). 2pts(7) Lets assume you are conducting an experiment to determine the effect of a new drug on the incidence of epileptic seizures.

You select 20 epileptics from the 150 epileptics being treated at a nearby hospital and administer the drug to them. You record the number of seizures in each of the 20 subjects for one month. The 20 subjects constitute frequency. 2pts (8) Lets assume you are conducting an experiment to determine the effect of a new drug on the incidence of epileptic seizures. You select 20 epileptics from the 150 epileptics being treated at a nearby hospital and administer the drug to them. You record the number of seizures in each of the 20 subjects for one month.

The average (mean) number of seizures for the 20 subjects is called nominal categorical. 2pts 9) The variable that the experimenter manipulates is called the dependent variable.2pts (10) A psychologist is interested in the social interactions of preschool children. She measures the number of verbal interactions that each child at a preschool engages in during a day. Here is the frequency distribution of the data. (2pts)The real limits of the interval 56-65 are b. 55.5 – 65.5 a.56.5-65.5c.55-67b.55.5-65.5d.56-65 (11) Given the distribution of grouped scores shown in the following table (2pts)How many occurrences are there for the interval 60-69? 21 (12) Given the distribution of grouped scores shown in the following table (2pts)N equals 139 (13) Given the distribution of grouped scores shown in the following table (2pts)The cumulative frequency of 115 indicates that 115 scores fall below 60. (14) An industrial psychologist observed 8 drill-press operators for one working day.

She recorded the number of times each operator pressed the "faster" button instead of the "stop" button to determine whether the design of the control panel was contributing to the high rate of accidents in the plant. The resulting scores were as follows: (2pts)5, 2, 8, 2, 3, 2, 4, and 12: The mode for this distribution is 12 (15) Given the following set of scores (5pts)X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1What is the mean? 8 (16) An economics test was given and the following sample scores were recorded:IndividualABCDEFGHIJScore121271091213898The mean of the distribution is 10 (5pts) (17) Assume the following are scores in a 100-point achievement test: (12pts)a.

What is the range of the distribution? 58b.Since there is no definitive rule for determining how many class intervals to divide data into, one generally plays with the data or is told how many intervals to use. If you were told to group the above data into approximately 12 intervals of equal width, how wide would the class intervals be. 0 – 7 … 88 – 95 Using the value just calculated for I = 8.0 what would be the lower apparent limit of the lowest class interval? -0.5c.Using 12 intervals construct a table that shows the frequency distribution of grouped scores, the corresponding cumulative frequency distribution, and the corresponding cumulative percentage distribution.

Class IntervalsFrequencyCumulative Percentage0 – 703.58 – 15015.516 – 23023.524 – 31031.532 – 39239.540 – 47647.548 – 55455.556 – 631063.564 – 71471.572 – 79479.580 – 87787.588 - 95995.5 (18) What is wrong with the following frequency distribution? (2pts)The class interval of the frequency distribution table is not consistent (19) A car company wanted to know how many miles per gallon an experimental car got after a series of tests. The following data were obtained. (5pts)Miles per gallon: 31.2, 28.6, 36.4, 37.3, 30.1, 29.0, 32.7, 31.9a.

What is the mean number of miles per gallon obtained in this sample? 32.15b.What is the value of  X= 257.2 and  X2= 8341.56?What is the standard deviation of this sample?= 3.22003 (20) What are the critical values of t for each of the following values of N and alpha using a non-directional hypothesis? (1pt each)N a.120.05b.200.01c.20.05d.50.02e.190.01Answer: cNow using a directional hypothesis?N f.130.025g.170.005h.80.05i.150.01j.100.05Answer: g.Work CitedCaria, Mario. Measurement Analysis: An Introduction to the Statistical Analysis of Laboratory Data in Physics, Chemistry and the Life Sciences.

London [u.a.: Imperial College Press, 2000. Print.Rajamanickam, M. Statistical Methods in Psychological and Educational Research. New Delhi: Cocept Publishing, 2001. Print.Zeisset, Ray M, and Ray M. Zeisset. Statistics & Measurement: An Introduction. Gainesville, FL: Center for Applications of Psychological Type, Inc, 2009. Print.