ECN221 Final Exam Updated Version 2025

________ data use descriptive terms to measure or classify something of interest. - Qualitative Which levels of measurement are considered quantitative data? - -interval and ratio A respondent of a survey is asked whether their most recent dining experience was excellent, good, Fair, or poor. The person indicates that the experience was "good". This is an example of - -ordinal ________ data are values collected from a number of subjects (firms, individual, states, regions, and So forth) during a single time period. - -cross sectional The proportion of customers that rate their latest airline experience as "excellent" is an example of - -descriptive stats Bridgestone would like to estimate the average tread life of a particular brand of automobile tire. Bridgestone selects a random sample of fifty customers who have purchased this tire and asks these Customers about the tred life of their tires. Using the information from this sample of customers Bridgestone draws a conclusion about the average tread life of the total population of tires . This is - -inferential stats A ________ is a portion of a population that is representative of the population from which it is Selected. - -sample ________ are values that can take on any real numbers, including numbers that contain Decimal points. This data is often the result of measuring observations rather than Counting them - -continuous ________ totals the proportion of observations that are less than or equal to the class at Which you are looking. - -Cumulative relative frequency dist The class ________ represent the minimum and maximum values for each class of a frequency Distribution using grouped quantitative data - -boundries ECN221 ECN221 The ________ is found by first determining the index point, i = 0.5(n), where n is the number of data Points - -median Which one of the following statements is true for a left-skewed distribution? - -mean is less than median Comparing the consistency between two data sets when their means are very different is best done With the - -coefficient variation ________ probability is the probability of Event A occurring without any additional information That could influence the event. - -prior A hotel manager is making a presentation to justify adding more staff. She has made charts and graphs, the type of statistical analysis she used is? - -descriptive ____ are data values based on observations that can be counted are are typically represented by whole numbers - -discrete The ____ measures a distributions SD in terms of its percentage to the mean - coefficient of variation A histogram should be computed from ____ data - -quantitative A line chart is most appropriate for - -time series data If 2 events are dependent then - -P(A I B) not equal to P(A) A collage data base includes the number of people who are enrolled in each class the college offers is and example of - -ratio data A _____ represents all possible subjects that are of interest in a particular study - population _______ display the proportion of observations of each class relative to the total number - -relative frequency distribution A ________ distribution is useful for calculating the probability that a certain number of events will Occur over a specific interval of time or space. - -poisson The mean and the variance are equal for a ________ probability distribution - -poisson The ________ probability distribution is bell-shaped and symmetrical - -normal ECN221 ECN221 A smaller standard deviation for the normal probability distribution results in - -a skinnier curve that is tighter and taller around the mean Which of the following statements is true regarding z-scores for the normal probability Distribution? - -z-scores are negative for values of x that are less than the distribution mean The shape of the uniform probability distribution is - -flat ________ errors can occur as a result of a questionnaire that contains ambiguous questions - -non sampling The Central Limit Theorem (CLT) states that the - -sample means of large-sized samples will be normally distributed regardless of the shape of Their population distributions. For a sample size of two or more, the standard error of the mean must be - -less than the population standard deviation. The _______ probability distribution is useful when the majority of the data tend to be in the middle of the distribution - -normal Which of the following probability distributions is discrete - -binomial The shape of an exponential distribution is - -right skewed As the size of the sample decreases - -the standard error of the mean becomes larger The sampling distribution of the proportion follows the ________ probability distribution - -binomial When calculating a confidence interval for the mean using a sample of 30+ and an unknown population SD, the ___ is used - -Students T-dist A ________ is an interval estimate around a sample mean that provides us with a range within which the true population mean is expected to lie - -confidence interval of the mean The _____ is the amount added and subtracted to the point estimate to form the confidence interval - -margin of error The confidence interval gets ______ if the confidence level ___ - -wider, increases When the population SD is _____ we substitute the ______ in its place to calculate the _______ - -unknown, sample SD, standard error of the mean ECN221 ECN221 ______ errors can occur as a result of a questionnaire that contains ambiguous questions - -non sampling The larges the SD for the normal probability dist results in - -a fatter curve that is more spread out around the mean and not as tall The _____ probability is bell-shaped and symmetrical - -Normal As the size of the sample increases - -the standard error of the mean becomes smaller What is the mean of the standard uniform dist - -.5 If a study is set up in a way that a sample of people is surveyed to determine whether they have ever used a particular product, the likely probability dist that would describe the random variable, the number who