Statistics Sample Final Exam PDF

Statistics Sample Final Exam Instruction: Encircle the letter of the correct answer. 1. Find the median of the call received on 7 consecutive days 11,13, 17, 13, 23,25,19 a. a. 13 b. b. 23 c. c. 25 d. d.17 2. Which one of the following v...

Statistics Sample Final Exam Instruction: Encircle the letter of the correct answer. 1. Find the median of the call received on 7 consecutive days 11,13, 17, 13, 23,25,19 a. a. 13 b. b. 23 c. c. 25 d. d.17 2. Which one of the following variables is not categorical? a. Age of a person. b. b. Gender of a person c. c. Choice on a test item: true or false. d. d. Marital status 3. If the values of two variables move in the opposite direction, ___________ a. The correlation is said to be linear b. The correlation is said to be non-linear c. The correlation is said to be positive d. The correlation is said to be negative 4. A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation: I = 50,000 - 8X.The above equation implies that an a. increase of $1 in price is associated with a decrease of $8 in sales b. increase of $8 in price is associated with an increase of $8,000 in sales c. increase of $1 in price is associated with a decrease of $42,000 in sales d. increase of $1 in price is associated with a decrease of $8000 in sales 5. Calculate the range of the given sets of data 7,47,8,42,47,95,42,96,2 (formula: max – min) a. 6 b. 94 c. 71 d. 84 6. When the correlation coefficient, r, is close to one: a. there is no relationship between the two variables b. there is a strong linear relationship between the two variables c. it is impossible to tell if there is a relationship between the two variables d. the slope of the regression line will be close to one 7. Which of the given plots is suitable for testing the linear relationship between a dependent and independent variable? a. Barchart b. Scatter plot c. Histograms d. All of the above. 8. Find the mode and median of the 9 consecutive number 7,12,8,14,21,23,27,7,11 a. 12,9 b. 7,9 c. 7,12 d. 9,11 9. Which of the following is a branch of statistics? a. Descriptive statistics b. Inferential statistics c. Correlation d. Both A and B 10. What are the variables whose calculation is done according to the weight, height, and length known as? a. Flowchart variables b. Discrete variables c. Continuous variables d. Measuring variables 11. The correlation coefficient is used to determine: a. A specific value of the y-variable given a specific value of the x-variable b. A specific value of the x-variable given a specific value of the y-variable c. The strength of the relationship between the x and y variables d. None of these 12. If the correlation coefficient is a positive value, then the slope of the regression line a. must also be positive b. can be either negative or positive c. can be zero d. can not be zero 13. A residual plot: a. displays residuals of the explanatory variable versus residuals of the response variable. b. displays residuals of the explanatory variable versus the response variable. c. displays explanatory variable versus residuals of the response variable. d. displays the explanatory variable versus the response variable. 14. If the values of two variables move in the same direction, ___________ a. The correlation is said to be non-linear b. The correlation is said to be linear c. The correlation is said to be negative d. The correlation is said to be positive 15. Which of the following techniques is an analysis of the relationship between two variables to help provide the prediction mechanism? a. Standard error b. Correlation c. Regression d. None of the above 16. The degree of peakedness or flatness of a unimodel distribution is called: a. Skewness b. Symmetry c. Dispersion d. Kurtosis 17. What is the meaning of the testing of the hypothesis? a. It is a significant estimation of the problem b. It is a method of making a significant statement c. It is a rule for acceptance or rejection of the hypothesis of the research problem d. None of the above 18. What is the skewness of normal distribution? a. 0 b. 1 c. c. -1 d. d. 2 19. The measurements of spread or scatter of the individual values around the central point is called: a. Measures of dispersion b. Measures of central tendency c. Measures of skewness d. Measures of kurtosis 20. The measure of dispersion which uses only two observations is called: a. Mean b. Median c. Range d. Coefficient of variation 21. The range of the scores 29, 3, 143, 27, 99 is: a. 140 b. 143 c. 146 d. 70 22. The average of squared deviations from mean is called: a. Mean deviation b. Variance c. Standard deviation d. Coefficient of variation 23. Standard deviation is always calculated from: a. Mean b. Median c. Mode d. Lower quartile 24. In case of positively skewed distribution, the extreme values lie in the: a. Middle b. Left tail c. Right tail d. anywhere 25. The lower and upper quartiles of a distribution are 80 and 120 respectively, while median is 100. The shape of the distribution is: a. Positively skewed b. Negatively skewed c. Symmetrical d. Normal 26. In a symmetrical distribution Q1 = 20 and median= 30. The value of Q3 is: a. 50 b. 35 c. 40 d. 25 27. In a normal distribution, what percentage of the data falls within one standard deviation of the mean? a. 34% b. b. 50% c. c. 68% d. d. 95% 28. The area under the normal curve represents: a. Variance b. Skewness c. Probability d. Range 29. Which measure indicates the degree of symmetry in a probability distribution? a. Skewness b. b. Kurtosis c. c. Variance d. d. Standard deviation 30. A normal distribution is perfectly symmetrical around the: a. Median b. Mode c. Mean d. Quartile 31. What is the skewness of a perfectly symmetrical distribution? a. 0 b. 1 c. -1 d. It cannot be determined 32. If a dataset has a positive skewness, it means: a. It is symmetrical b. Its tail extends more to the right c. Its tail extends more to the left d. It has a kurtosis of 0 33. Kurtosis measures the: a. Symmetry of a distribution b. Tendency of a distribution's tails to be heavy or light c. Spread of a distribution d. Skewness of a distribution 34. What does a positive kurtosis value indicate about a distribution? a. The distribution is perfectly symmetrical b. The distribution has heavy tails c. The distribution has light tails d. The distribution is highly skewed 35. In a normal distribution, what is the value of kurtosis? a. 0 b. 1 c. -1 d. It varies 36. What does a leptokurtic distribution indicate? a. Heavy-tailed distribution b. Light-tailed distribution c. Symmetrical distribution d. Negative skewness 37. What is the probability of an event that is certain to occur? a. 0 b. 1 c. 0.5 d. -1 38. What does the central limit theorem state about the distribution of sample means? a. They will approach a normal distribution as sample size increases b. They will always be skewed to the right c. They will approach a uniform distribution as sample size increases d. They will always follow a normal distribution 39. Which of the following is NOT a characteristic of a normal distribution? a. Bell-shaped curve  b. Symmetrical around the mean c. Mean, median, and mode are equal d. d. Long tails on either side 40. What is the main purpose of statistics? a. Predict the future b. Summarize and analyze data c. Make graphs d. Calculate averages 41. Which of the following represents a population parameter? a. Mean of a sample b. Standard deviation of a population c. Median of a data subset d. Proportion from a sample 42. The process of selecting a subset of individuals from a population is called: a. Estimation b. Sampling c. Data Collection d. Experimentation 43. What is the branch of statistics concerned with drawing conclusions from data? a. Descriptive Statistics b. Inferential Statistics c. Probability d. Applied Mathematics 44. The probability of an impossible event is: a. 0 b. 1 c. -1 d. Any value between 0 and 1 45. If two events cannot happen at the same time, they are called: a. Independent b. Dependent c. Mutually Exclusive d. Complementary 46. The sum of probabilities of all possible outcomes of an experiment is: a. Less than 1 b. 1 c. Greater than 1 d. Dependent on the sample size 47. In a fair coin toss, what is the probability of getting heads? a. 0.25 b. 0.5 c. 0.75 d. 1 48. What is the probability of rolling a 4 on a fair six-sided die? a. 1/2 b. 1/4 c. 1/6 d. 1/12 49. Which measure of central tendency is most affected by extreme values?** a. Mean b. Median c. Mode d. Range 50. The spread of data in a dataset is measured by a. Mean b. Standard deviation c. Median d. Mode 51. What is the mode of the dataset {2, 3, 3, 4, 5}? a. 3 b. 4 c. 5 d. 2 52. The range of a dataset is calculated as a. Highest value - Lowest value b. Mean - Median c. Median - Mode  d. Highest value + Lowest value 53. The null hypothesis is usually a statement of: a. No effect or no difference b. Significant effect c. Experimental manipulation d. Population variability 54. Which test is used to compare the means of two independent groups? a. t-test b. Chi-square test c. ANOVA d. Regression analysis 55. What does a p-value represent? a. The probability of rejecting the null hypothesis b. The likelihood of observing the data if the null hypothesis is true c. The effect size d. The confidence level 56. What is the critical value in hypothesis testing? a. The threshold to decide significance b. The mean of the data c. The p-value d. The standard error 57. The measure of how two variables move together is called a. Regression b. Correlation c. Standard Deviation d. Central Tendency 58. The slope in a simple linear regression represents a. The intercept b. The rate of change in the dependent variable per unit change in the independent variable c. The standard error d. The residual sum of squares 59. Which statistic indicates the strength and direction of a linear relationship? a. t-value b. r (correlation coefficient) c. F-statistic d. p-value 60. What is the value of r if there is no correlation? a. -1 b. 0 c. 1 d. Undefined 61. In multiple regression, the dependent variable is predicted based on a. One independent variable b. Multiple independent variables c. The sample size d. The median 62. A box plot is used to show a. Trends over time b. Measures of central tendency and spread c. Relationships between variables d. Frequencies of data points 63. Which chart is best for categorical data? a. Histogram b. Bar chart c. Scatter plot d. Line graph 64. Outliers are best identified using a. Scatter plots b. Box plots c. Pie charts d. Line graphs 65. What type of chart is used to display parts of a whole? a. Bar chart b. Pie chart c. Scatter plot d. Histogram 66. A company wants to test whether three different training programs produce different levels of employee productivity. Which statistical test should they use? a. Z-test b. T-test c. ANOVA d. Chi-square test 67. A researcher conducts a study to compare the average test scores of students in three different teaching methods. What is the null hypothesis for ANOVA? a. All group means are equal. b. At least one group mean is different. c. All variances are equal. d. All medians are equal. 68. If the F-ratio in an ANOVA test is large and the p-value is less than 0.05, what conclusion can be made? a. Accept the null hypothesis. b. Reject the null hypothesis; at least one group mean is different. c. The groups are identical. d. Increase the sample size. 69. Which post-hoc test is commonly used after a significant ANOVA result to determine which groups differ? a. T-test b. Tukey's HSD c. Z-test d. Pearson correlation 70. In a one-way ANOVA, how many independent variables are analyzed? a. 1 b. 2 c. 3 d. None 71. A professor compares the test scores of students from three campuses. ANOVA shows \( F(2, 87) = 5.23, p = 0.003 \). What does this mean? a. There is no difference between campuses. b. At least one campus has significantly different test scores. c. The sample size is too small. d. The test is invalid. 72. What assumption must be met to conduct an ANOVA? a. All groups have equal sample sizes. b. The data must be ordinal. c. Groups have equal variances and are normally distributed. d. The data must be categorical. 73. In a study comparing satisfaction levels among four customer service methods, the ANOVA test yields \( p = 0.08 \). What is the conclusion? a. Reject the null hypothesis. b. Fail to reject the null hypothesis; there is no significant difference. c. Accept the alternative hypothesis. d. Repeat the study with more data. 74. How does a two-way ANOVA differ from a one-way ANOVA? a. It compares means of more than three groups. b. It examines the interaction effect between two independent variables. c. It does not assume normality. d. It only works for large samples. 75. A researcher wants to compare blood pressure levels before and after using three types of medication. What type of ANOVA should they use? a. One-way ANOVA b. Repeated measures ANOVA c. Two-way ANOVA d. MANOVA 76. A teacher wants to compare the mean test scores of two groups of students. Which test is appropriate? a. Z-test b. T-test c. ANOVA d. Chi-square test 77. What is the main difference between an independent t-test and a paired t-test? a. Independent t-test compares two unrelated groups, while paired t-test compares matched data. b. Paired t-test compares more than two groups. c. Independent t-test is only for large samples. d. Paired t-test does not require normality. 78. A researcher measures the effect of a new diet by comparing the weights of participants before and after the intervention. What statistical test should they use?  a. Independent t-test b. Paired t-test c. One-way ANOVA d. Z-test 79. The p-value in a t-test is 0.045. If the significance level is 0.05, what should the researcher conclude? a. Accept the null hypothesis. b. Reject the null hypothesis. c. Increase the sample size. d. Fail to reject the null hypothesis. 80. In a two-sample t-test, the null hypothesis states a. The two population means are equal. b. The two sample means are different. c. The variances are equal. d. The data are normally distributed. 81. Which assumption is not required for a t-test? a. Random sampling b. Normality of data c. Equal sample sizes d. Homogeneity of variance for independent t-tests 82. A researcher uses an independent t-test to compare test scores between males and females. The test yields \( t(48) = 2.02, p = 0.05 \). What does this indicate? a. No significant difference exists. b. There is a significant difference at the 0.05 level. c. The sample size is too small. d. The variance is unequal. 83. The calculated t-value is larger than the critical t-value. What does this indicate? a. Fail to reject the null hypothesis. b. Reject the null hypothesis. c. Increase the sample size. d. Conduct an ANOVA instead. 84. What type of t-test is used to compare a sample mean with a known population mean? a. Independent t-test b. One-sample t-test c. Paired t-test d. Two-way ANOVA 85. A z-test is appropriate when the sample size is a. Less than 30 b. Greater than or equal to 30 c. Less than 50 d. Always appropriate regardless of sample size 86. The primary difference between a z-test and a t-test is a. The z-test is for small samples. b. The z-test is used when population standard deviation is known. c. The t-test requires paired data. d. The z-test assumes unequal variances. 87. A z-test is used to compare a. Two sample means b. A sample mean with a population mean c. Variances between groups d. Correlations 88. If a z-test produces \( z = 1.96 \) at \( \alpha = 0.05 \), what conclusion can be made? a. Reject the null hypothesis. b. Fail to reject the null hypothesis. c. Increase the sample size. d. Decrease the significance level. 89. A researcher uses a z-test for proportions and gets \( p = 0.001 \). What does this mean? a. The null hypothesis is likely true. b. The result is statistically significant. c. Increase the sample size. d. The alternative hypothesis is rejected. 90. What is the z-score for a value of 85, if the population mean is 70 and the standard deviation is 10? a. 1.5 b. 2.0 c. 1.0 d. 0.5 91. A researcher uses a z-test for a sample size of 100 and calculates \( z = 3.2 \). What does this suggest? a. The sample mean is significantly different from the population mean.  b. The null hypothesis cannot be rejected. c. The result is not statistically significant. d. There is a Type II error. 92. What is the critical z-value for a two-tailed test at \( \alpha = 0.05 \)? a. ±1.96 b. ±2.58 c. ±1.645 d. ±1.00 93. In a z-test, if the calculated z-value is less than the critical z-value, you should a. Reject the null hypothesis. b. Fail to reject the null hypothesis. c. Conduct a t-test instead. d. Increase the sample size.