Business Statistics Exam Questions And Answers Verified 100% Correct

Business Statistics Exam Questions And Answers Verified 100% Correct A teacher gave a statistics test to a class of Geography students and computed the measures of central tendency for the test scores. Which of the following statements cannot be an accurate description of the scores? - ANSWER -The majority of students had scores above the median. Which of the following sets of scores has the greatest variability ( range)? A. 2, 5, 8, 11 B. 13, 13, 13, 13 C. 20, 25, 26 ,27 D. 42, 43, 44, 45 - ANSWER -A. 2, 5, 8, 11 Which of following statements is the most accurate description for the concept of standard deviation? - ANSWER -The average distance between a score and the mean. What is varience of for the following set of scores: 2, 2, 2, 2, 2. - ANSWER -0 Normally distributed data are normally referred to as: - ANSWER - Bellshaped Take the formula Z = (X - μ)/σ, where μ is the mean of the population, X is the value of the element, Z is the z-score and σ is the standard deviation. What does this formula calculate? - ANSWER -Standard score. A population has a mean of μ=35 and a standard deviation of σ=5. After 3 points are added to every score in the population, what are the new values for the mean and standard deviation? - ANSWER -μ=38 and σ=5 Of the following Z-score values, which one represents the location closest to the mean? - ANSWER -Z=-0.3 If the scores on a test have a mean of 26 and a standard deviation of 4, what is the z-score for a score of 18? - ANSWER --2 A population has a μ=50 and σ=10. If these scores are transformed into z-scores, the population of z-scores will have a mean and standard deviation of: - ANSWER -μ=0 and σ=1 If all possible samples of size n=30 are selected from a population with μ=80 and σ=10 and the mean is computed for each sample, then what shape is expected for the distribution of sample means? - ANSWER -The sample means tend to form a normal-shaped distribution whether the population is normal or not. What is a definition of the standard error? - ANSWER -Standard deviation of sample means. If a researcher sets a level of significance at .05 (i.e. 5%), what does this mean? - ANSWER -Five times out of 100, a significant result will be found that is due to chance alone and not to true relationship. When does a researcher risk a Type I error? - ANSWER -Anytime H0 is rejected. Which of the following assumptions are required if an independent ttest is to be used? - ANSWER -Samples are drawn from a normally distributed population. Homogeneity of variances (equal variances).. The data are either interval or ratio scales. (All the above assumptions (A, B and C) are required.) What is the correct decision in a hypothesis if the data produce a tstatistic that is in the critical region? - ANSWER -Reject H0 How does the shape of the t distribution compare to the normal distribution? - ANSWER -The t distribution is flatter and more spread out, especially when n is small. Suppose you wanted to apply a one-tailed test as opposed to a twotailed test. How would you covert a significance of p = .284? - ANSWER -.284/2=.142 A research report summarizes the results of a t-test by stating: t(35)=5.2, p0.05. Which of the following is a correct interpretation of this report? - ANSWER -The H0 was rejected and the probability of a Type I error is less than .05. Which of the following is true about a 95% confidence interval of the mean of a given - ANSWER -There is a 95% chance that the population mean will fall within the limits of the confidence interval