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2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A 2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A 2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A 2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A 2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A 2024/2025 Business Statistics Final Test Exam Actual Exams Questions with 100% Correct Verified Answers Graded A
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The variance can never be a. zero b. larger than the standard deviation c. negative d. smaller than the standard deviation c. negative The binomial distribution is a continuous probability distribution. True or False? False The _____________ of an event is a number that measures the likely hood that an event will occur when an experiment is carried out. A. Outcome B. Probability C. Intersection D. Observation B. Probability A study in which researchers do not have control over the state of the independent variables is called a _______ study. A. Experimental B. Observational C. Independent D. Placebo B. Observational
The area under the standard normal curve between z=2 and z=3 is _______________ the area under the normal curve between z=0 and z=1. A. Less than B. Greater than C. Equal to D. A, B, or C above, depending on the value of the mean. E. A, B, or C above, depending on the value of the standard deviation. A. Less than If the random variable X is normally distributed, _________ percent of all possible observed values will be within three standard deviations of the mean. A. 68. B. 95. C. 99. D. 100 E. None of the above C. 99. A marginal probability is equivalent to a ___________ probability divided by a ____________ probability. A. Conditional, Joint B. Joint, Conditional C. Sample, Population D. Independent, Mutually exclusive B. Joint, Conditional ________________ is the science of using a sample to make generalizations about the important aspects of a population. A. Time series analysis B. Descriptive statistics C. Random sample D. Statistical inference
D. Statistical inference Which of the following keywords is most associated with a joint probability statement? A. "AND" B. "OR" C. "NOT" D. "GIVEN" A. "AND" Which of the following is NOT a common measure of variability? A. Median B. Variance C. Standard Deviation D. Range A. Median If the sample sizes are different in a two sample hypothesis test, then the samples must be _____________________. A. dependent B. normally distributed C. independent D. unreliable C. Independent Unlike the ____________________ hypothesis, the _________________ hypothesis is not assumed to be true at the outset of the hypothesis test. It is only supported if the sample evidence is significant. A. Alternative; null B. Null; alternative C. Alternate; zero D. Alternative; alternative B. Null; alternative
Which of the following is/ are (an) example(s) of a hypothesis in the context of statistics? I. The unemployment rate is greater then 5%. II. An airline claims that its "on time" arrival rate is greater than 95%. III. A mayor touts the fact that wind turbines provide greater than 20% of the power to a local community. IV. A manager of a popular restaurant claims that her restaurants table turnaround time has decreased within the last quarter by at least 10 minutes. A. Only I, III, and IV B. Only !, II, and IV C. Only II and III D. All four D. All four For a left tailed hypothesis test, the p-value is the area under the normal curve_______________. A. That includes the test statistic (the tests "data" value) B. To the right of the test statistic (the tests "data" value) C. That includes all possible values of z D. To the left of the test statistic (the tests "data" value) D. To the left of the test statistic (the tests "data" value) Consider a sampling distribution formed based on n = 3. The standard deviation of the population of all sample means is ______________ less than the standard deviation of the population of individual measurements σ. A. Always B. Sometimes C. Never D. Cant determine with the information provided A. Always Which of the following is an advantage of a confidence interval estimate over a point estimate for a population parameter? A. Interval estimates are more precise than point estimates
B. Interval estimates are less accurate than point estimates C. Interval estimates are both more accurate and more precise than point estimates D. Interval estimates tale into account the fact that the statistic being used to estimate the population parameter is a random variable D. Interval estimates tale into account the fact that the statistic being used to estimate the population parameter is a random variable A confidence interval increases in width as ..... A. The level of confidence increases B. n decreases C. s increases D. All of these D. All of these If a one sided null hypothesis is rejected for a single mean at a given significance level, the corresponding two - sided null hypothesis ( i.e., the same sample size, same standard deviation, and same mean) will _______________ be rejected at the sample significance level. A. Always B. Sometimes C. Never B. Sometimes A correlation coefficient describes the ________________ of dependency between two quantitative variables. A. Strength B. Direction C. Strength and Direction D. Causation C. Strength and Direction A regression analysis between weight ( y in pounds) and height ( x in inches) resulted in the following least squares line: y = 120 + 5x. This implies that if the height is increased by 1 inch, the weight is expected to.......
A. increase by 1 pound B. Decrease by 1 pound C. Increase by 5 pounds D. Decrease by 24 pounds C. Increase by 5 pounds, because Y = 120 + 5x Y = 120 + 5(1) Y = 120 + 5 Y = 125 Change in Y = 125-120= 5 What are the two branches of statistical science? Descriptive Statistics and Inferential Statistics normal distribution curve the bell-shaped curve that results from plotting continuous variation data on a graph. right skewed distribution A density curve where the right side of the distribution extends in a long tail; (mean > median) left-skewed distribution a distribution that has a concentration of data on the upper end and the tail on the left Qualitative Data Information describing color, odor, shape, or some other physical characteristic Quantitative Data numerical data Mean average Median
the middle score in a distribution; half the scores are above it and half are below it Mode the most frequently occurring score(s) in a distribution Range the difference between the highest and lowest scores in a distribution Variance standard deviation squared Standard Deviation a computed measure of how much scores vary around the mean score What three things measure variation? Range, Variance, and Standard Deviation Probability likelihood that a particular event will occur Complement P (A) + P ("NOT" A) = 1 Sample Space the set of all possible outcomes Event a collection of outcomes Union P (A or B ) "or" Intersection P ( A n B ) "and"
Marginal P ( A ) "only" A/ all Joint P ( A n B) "and" both/all Conditional P ( A /B ) "given" (A n B)/ B The MJC Equation M = J/ C Mutually Exclusive Events that cannot occur at the same time. Discrete random Variables Those usually obtained by counting. Binomial Distribution "2 possible outcomes"
Normal distribution a bell-shaped curve, describing the spread of a characteristic throughout a population Empirical Rule 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 z-score a measure of how many standard deviations you are away from the norm (average or mean) degrees of freedom Sample size - 1. Used for the vertical axis of the T chart Central Limit Theorem The theory that, as sample size increases, the distribution of sample means of size n, randomly selected, approaches a normal distribution. Random Sampling a sample that fairly represents a population because each member has an equal chance of inclusion Point Estimation estimate an unknown parameter using a single statistic (e.g. xˉ , p̂ ) confidence interval the range of values within which a population parameter is estimated to lie Margin of Error the range of percentage points in which the sample accurately reflects the population p-value The probability level which forms basis for deciding if results are statistically significant (not due to chance)