PSY 230 Midterm Review Exam - Questions and Answers

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PSY 230 Midterm Review Exam - Questions and Answers What level of measurement is being used when a researcher is collecting daily high temperatures? Nominal, Ordinal, Interval, or Ratio Interval, at... this level, a "zero" as a data value is a position on a scale. If the temperature is zero, that is a position on a thermometer. What level of measurement is being used when a researcher is collecting annual income of employees? Nominal, Ordinal, Interval, or Ratio Ratio, at this level, a "zero" as a data value implies NONE. If someone has zero dollars, they have NO money. What level of measurement is being used when a researcher is collecting a list of student names? Nominal, Ordinal, Interval, or Ratio Nominal, at this level the data is labels. The data cannot be put in any numerical order or ranking. What level of measurement is being used when a researcher is collecting survey results where movie attendees rated a movie using scale from 1 to 5 (1 = they hated the movie and a 5 = they loved the movie)? Nominal, Ordinal, Interval, or Ratio Ordinal, at this level data can be "ranked" or is a "rating" and can be put in order. What is the parameter? A numerical measurement describing a population. What is the statistic? A numerical measurement describing a sample. What type of sampling technique is being used when you select subjects at regular intervals (such as questioning every 5th student entering the building). Systematic When graphing data that consists of Nominal Data (labels), what types of graphs are often used? Bar graph, pie chart, Pareto chart What type of sampling technique is being used when the data is divided into subgroups and samples from each subgroup participate in the survey. Stratified What type of sampling technique is being used when the data is divided into subgroups and at least one of the subgroups has ALL of the subjects participate in the survey. Cluster When graphing data that consists of numerical values, what types of graphs are often used? Histrogram, dot plot, stem and leaf, time series chart Which of the following best describes the histogram of a skewed left distribution? A majority of the data falls to the right, with a tail forming to the left. The mean will be less than the median. How do you find the mean of a data set? You add all the data values up and then divide by how many data values are in the set. How do you find the median of a data set? You put the data in numerical order and then find the exact middle value. If there are two data values in the middle, you find the average of the two middle values to get the median. Find the mean for the following scores: 3, 7, 13, 8, 9, 8 Mean = 8 Mean = (3 + 7 + 13 + 8 + 9 + 8)/6 Mean = 48/6 Mean = 8 Find the median for the following scores: 3, 7, 13, 8, 9, 8 Put data in numerical order and then find the middle value. 3, 7, 8, 8, 9, 13 This data set has two middle values, so: (8 + 8)/2 = 8 Median = 8 A frequency distribution is created and one of the classes has limits of 12 - 20. What is the midpoint of the class? (12 + 20) / 2 32/16 Midpoint = 16 What proportion of the data falls less than or equal to 4? 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6 3 values have values of 4 or less. There are 12 values total. 3/12 = 0.25 Which measure of central tendency is most impacted by outliers? The mean A data set with a SMALL standard deviation will have data values ___________. A data set with a LARGE standard deviation will have data values ___________. Small standard deviation = data values close together Large standard deviation = data values spread out In a skewed left distribution, the mean is ________ the median. less than In a skewed right distribution, the mean is ________ the median. greater than What is the probability of rolling a number greater than or equal to 5 on a six-sided die? 2/6 = 1/3 If events A and B are independent, and P(A) = 0.3 and P(B) = 0.7, what is P(A and B)? P(A and B) = P(A) * P(B) = 0.3 * 0.7 = 0.21 Suppose a report states that 15% of students have to repeat their math course in college. What is the probability that 2 randomly selected students will both have to retake their math course? 0.15 * 0.15 =0.0225 [Show More]

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