Math 110 Elementary Statistics (Module 2 Questions and Answers A+ Graded 100% Verified)

Math 110 Elementary Statistics (Module 2 Questions and Answers A+ Graded 100% Verified) Frequency distribution Correct Ans: A tabular summary of data showing the number (frequency) of observations in each of several distinctive (nonoverlapping) categories or classes. relative frequency Correct Ans: A ratio that compares the frequency of each category to the total. frequency of the class / n where n = total count of all classes relative percentage Correct Ans: percentage of time the value occurs in the sample or population relative frequency x 100 charting Correct Ans: a means to represent frequencies visually column chart Correct Ans: Data graphed as a series of vertical bars x-axis: class y-axis: frequency of class bar chart Correct Ans: Data graphed as a series of horizontal bars x-axis: frequency of class y-axis: class pie chart Correct Ans: a chart that shows the relationship of a part to a whole best suited for the distributions focused on the proportions 3 step method to group numerical data into classes Correct Ans: 1. determine the number of classes to be evaluated 2. determine the width of each class 3. determine the limits of each class Number of classes Correct Ans: (usu b/w 5 and 20) less than 25 > 5 to 6 25 to 50 > 7 to 14 More than 50 > 15-20 Width of class Correct Ans: approx width = (largest data value - smallest data value) / # of classes qualitative data Correct Ans: frequency distributions relative frequency distributions percent frequency distributions Graphical: bar, column, pie charts quantitative data Correct Ans: frequency distributions relative frequency distributions percent frequency distributions Graphical: histograms positive relationship Correct Ans: an association between two variables in which they increase or decrease together negative relationship Correct Ans: an association between two variables in which one increases while the other decreases no relationship Correct Ans: as one variable increases the other stays the same measures of central tendency Correct Ans: mean, median, mode "typical" or "average" value of a data set sample mean Correct Ans: x bar the arithmetic average value of the responses on a variable (sum of values / number of observations) population mean Correct Ans: μ (mu) calculated mean of the entire population (sum of values in population / N = number of observations in pop) median Correct Ans: midpoint the middle score in a distribution; half the scores are above it and half are below it odd = middle number even = average of two middle numbers mode Correct Ans: The value that occurs most frequently in a given data set. percentile Correct Ans: Specific point in a distribution of data that has a given percentage of cases below it. quartile Correct Ans: A division of the total into four intervals, each one representing one-fourth of the total. median is Q2 median of lower half is Q1 median of upper half is Q3 interquartile range Correct Ans: The difference between the upper and lower quartiles. Q3-Q1 population variance Correct Ans: the difference between each data point in a data set and the population mean of the data set N, number in the population sample variance Correct Ans: the difference between each data point in a data set and the sample mean of the data set n, which is the number in the sample deviation about the mean Correct Ans: calculated difference between the data value and the mean sample standard deviation Correct Ans: the positive square root of the variance population standard deviation Correct Ans: the square root of the population variance coefficient of variation Correct Ans: Standard deviation / mean x 100 (expressed as percentage) how the size of the standard deviation compares to the mean of the data set z-score Correct Ans: the number of standard deviations a particular score is from the mean empirical rule (bell curve) Correct Ans: 68.27 - 95.45 - 99.73 The rules gives the approximate % of observations w/in 1 standard deviation (68%), 2 standard deviations (95%) and 3 standard deviations (99.7%) of the mean when the histogram is well approx. by a normal curve sample covariance Correct Ans: Sxy measures the direction of the linear relationship between two variables sxy > 0 Correct Ans: positive slope (variables increase together) most values in QI and QIII sxy < 0 Correct Ans: negative slope (increase one v, decrease other) most values in QII and QIV sample correlation coefficient Correct Ans: r, varies between -1 (strong neg) and 1 (strong pos) measures both the strength and direction of the linear relationship between two variables