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Statistics for Business Final Exams 2024/2025 Actual Exams Questions with 100% Correct Verified Answers Graded AStatistics for Business Final Exams 2024/2025 Actual Exams Questions with 100% Correct Verified Answers Graded AStatistics for Business Final Exams 2024/2025 Actual Exams Questions with 100% Correct Verified Answers Graded AStatistics for Business Final Exams 2024/2025 Actual Exams Questions with 100% Correct Verified Answers Graded AStatistics for Business Final Exams 2024/2025 Actual Exams Questions with 100% Correct Verified Answers Graded A
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If a null hypothesis is rejected at 1% level of significance (α), what will be done at 5% level of significance? a. the null will never be rejected. b. the null may be rejected. c. none of these. d. the null will always be rejected The 50th percentile is always equal to the: a. third quartile b. mean c. median d. mode C Say, A and B are independent events. If P(A) = 0.3, P(B) = 0.4. P(B¦A) =? a. 1. b.. c. 0. d.. C A graphical display of the relationship between two quantitative variables in which one variable is shown on the horizontal axis and the other variable is shown on the vertical axis is called :
a. pie chart b. histogram c. bar chart d. scatter plot D
. ...................... data use labels or names to identify categories of like items. a. quantitative data b. ratio data c. categorical data d. interval data C The following represents the probability distribution for the daily demand of microcomputers at a local store: Demand Probability 0 0. 1 0. 2 0. 3 0. 4 0. The expected value (probabilistic mean) of the daily demand is: a. 3, because 4 is the least likely to happen. b. 1. c. 1, since it has the highest probability d. 2 B
The intersection of two mutually exclusive events a. can be any value between 0 to 1 b. must always be equal to 0 c. must always be equal to 1 d. can be any positive value B For a one-tailed test (upper tail), a sample size of 26 for α =0.10, tα =? (refer to T table) Select one: a. - 1. b. - 1. c. 1. d. 1. C The data that on which basic arithmetical operations can be done are: Select one: a. Categorical data b. None of these. c. quantitative data d. Qualitative data C
. The level of significance (alpha) is the: a. same as the confidence coefficient b. probability of Type II error c. same as the p-value A procedure used to develop the estimated regression equation by minimizing the sum of squared residuals is called:
a. maximum likelihood method. b. generalized squares method. c. least squares method. d. mean square method C
. Given: P(S) = 0.3, P(W) = 0.2, P(S∩W) = 0.12. Find the value for P(S υ W): (formulas for addition rules are given. Use the appropriate one to answer the above question: Rule of Addition for non-mutually exclusive events: P(A∪B) = P(A) + P(B) - P(A∩B) Rule of Addition for mutually exclusive events: P(A∪B) = P(A) + P(B) ) Select one: a. 0. b. 0. c. 0. d. 0. D Consider the following hypothesis test for a population proportion: H0: p = 0. Ha: P ≠ 0.20. A sample of 400 provided a sample proportion p¯ = 0.175. At α = 0.05, what is your conclusion using the critical value approach? a. more information is needed b. we do not reject the null c. we reject the null d. we cannot make any decision C The numbers of hours worked (per week) by 400 statistics students are shown below. Number of Hours Frequency
The number of students working 19 hours or less is Select one: a. 80 b. 100 c. 180 d. 300 B Histograms are used for the display of ......... data and Bar charts are used for the display of ........ data. Select one: a. discrete, continuous b. qualitative, quantitative c. continuous, discrete d. quantitative, qualitative D
. The sum of the relative frequencies for all classes in grouped data will always equal Select one: a. the number of classes b. one c. any value larger than one d. the sample size B Say, 3 customers enter a store. On the basis of past experience, the store manager estimates the probability that any one customer will make a purchase is 0.30. What is the probability that two of the next three customers will make a purchase? (hint: this is a binomial case with n = 3, x = 2, and p = 0.30. P(2) = ?) The binomial formula is binomialprobabilityformula)
Select one: a. 0. b. 0. c. 0. d. 0.
. For a two-tailed test about the population mean when sigma is known with a sample size of 40, the null hypothesis will fail to be rejected at the 5% level of significance if the test statistic is (given: critical value for two sided test for 5% level of significance ±1.96) (for the formula: see the test-sheet) Select one: a. greater than 1. b. between - 1.96 and 1. c. less than 1. d. greater than - 1. B The variable such as weight of a person can be described as Select one: a. binomial random variable b. continuous random variable c. discrete random variable d. qualitative random variable B Of which probability distribution the are following properties?
c. standard normal d. normal A
. Which of the following is NOT an ideal measure of center of data if huge outliers exist? Select one: a. mean b. none of these. c. mode X d. median Suppose we select randomly one of the first 100 elements from the population list. Other sample elements are identified by starting with the first sampled element and then selecting every 100th element after the first randomly selected element. Such a sampling method is called a. stratified sampling b. convenience sampling c. simple random sampling d. systematic sampling D A researcher has collected the following sample data: 5, 12, 6, 8, 5, 6, 7, 5, 12, 4. The median is: a. 5 b. 7 c. 6 d. 8 C A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the a. approximation theorem b. central limit theorem
c. central normality theorem d. normal probability theorem B The scale of measurement that is used to rank order the observation for a variable is called the a. nominal scale b. ordinal scale c. interval scale d. ratio scale B If you flip a coin, Head or Tail may occur. P(H ∩ T) =? a. 0. b. 1 c. 0. d. 0 D X is a normally distributed random variable with mean 112 and standard deviation 15. Find the probability that X takes a value between 100 and 125. In other words, P(100<X<125) =? Select one: a. 0.4948 X b. 0. c. 0. d. 0. In a random sample of 144 observations, p¯= 0.9. The 95% confidence interval for the population proportion is Select one: a. 0.876 to 0. b. 0.898 to 0.
c. 0.851 to 0. d. 0.1 to 0. C A linear model is determined to be = 7 + 2 x. The coefficient of determination equals .49. Determine the correlation coefficient for the model. Select one: a. +.7 or - 0. b. 0. c. - 0. d. - 2 A
. A portion of the population selected to represent the population is called a. a census b. descriptive statistics c. statistical inference d. a sample D A numerical measure of the strength of linear relationship between two variables is the Select one: a. variance b. standard deviation c. coefficient of variation d. correlation coefficient D The proportion of the variability in the dependent variable y that is explained by the estimated regression equation is called Select one: a. residual b. correlation coefficient
c. coefficient of determination d. standardized residual A uniform probability distribution is a continuous probability distribution where the probability that the random variable assumes a value in any interval of equal length is Select one: a. none of these alternatives is correct. b. different for each interval c. at least one d. the same for each interval D Data collected at the same or approximately the same point of time is called a. quantitative data b. time series data c. qualitative data d. cross-sectional data
. If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect a. the sample size to increase b. the size of the confidence interval to increase c. the size of the confidence interval to decrease d. the size of the confidence interval to remain the same B . A linear regression model is estimated to be = 7 - 2 x. If x takes a value of 2, y can be expected to take the value Select one: a. 3 b. 11 c. - 15 d. 15
In order to estimate the average time spent on the computer terminals per student at a local university, data were collected for a sample of 81 business students over a one week period. Assume the population standard deviation is 1.2 hours. If the sample mean is 9 hours, find the the 95% confidence interval. (formula for confidence interval = point estimate ± margin of error, where margin of error = z_(a/2)*σ/√n and z_(a/2) for 95% confidence interval = 1.96) Select one: a. 7.04 to 110.96 hours b. 7.36 to 10.64 hours c. 8.74 to 9.26 hours d. 7.80 to 10.20 hours C Which of the following is NOT a characteristic of the normal probability distribution? (Note: it is NOT about the standard normal distribution) a. Total area under the curve is 0.5. b. The mean, median, and the mode are equal c. Approximately, 95% of the area under the curve lies between ± 2 standard deviations. d. The distribution is symmetrical The standard deviation of a sample of 100 observations equals 64. The variance of the sample equals Select one: a. 4, b. 8 c. 6400 d. 10 A
. Z is a standard normal random variable. The P (1.20 ≤ Z ≤ 1.50) equals (hint: find the area between 1.20 and 1.50 using the z-table) (refer to z table)
Select one: a. 0. b. 0. c. 0. d. 0. C The population mean is an example of a a. a formula b. a small population c. a statistic d. a parameter D If we accept Ho when Ha is true, we make a. type II error b. type I error c. correct conclusion d. none of these If a hypothesis is rejected at the 5% level of significance, it a. may be rejected or not rejected at the 1% level b. will always be accepted at the 1% level c. will always be rejected at the 1% level d. will never be tested at the 1% level A The probability distribution of the sample mean is called the a. random variation b. sampling distribution of the mean c. standard error d. central probability distribution B
According to the empirical rule, approximately ............ of the data values will be within ±one standard deviation of the mean. a. 97.1% b. 95% c. 68% d. 99.7% C The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hour Frequency 0 - 9 20 10 - 19 80 20 - 29 200 30 - 39 100 The interpretation of the cumulative relative frequency for the class of 20 - 29 is Select one: a. 200 students work between 20 and 29 hours per week. b. 75% of all the students work between 0 and 29 hours per week. c. 400 students work between 0 and 29 hours per week. d. 50% of all the students work between 20 and 29 hours per week. If SSR =10 and SST = 15, R2 equals to : a. 0. b. 1. c. 15 d. 10 A
. A simple random sample of 64 observations was taken from a large population. The sample mean and the standard deviation were determined to be 320 and 120 respectively. The standard error of the mean is (formula: if σ is known, standard error= σ/√n if σ is unknown, standard error= s/√n )
Select one: a. 1. b. 40 c. 15 d. 5 C