QMB 2100 – Business and Economic Statistics I QUIZ #5

Instructions: Select the best possible answer1. An experiment consists of determining thespeed of automobiles on a highway by the useof radar equipment. The random variable in thisexperiment is aa. discrete random variableb. continuous random variablec. complex random variabled. simplex random variable2. Variance isa. a measure of the average, or central value ofa random variableb. a measure of the dispersion of a randomvariablec. the square root of the standard deviationd. the sum of the squared deviation of dataelements from the mean3. A measure of the average value of a randomvariable is called a(n)a. varianceb. standard deviationc. expected valued. coefficient of variation4. For a uniform probability density function,a. the height of the function cannot be largerthan oneb. the height of the function is the same foreach value of xc. the height of the function is different forvarious values of xd. the height of the function decreases as xincreases5. The probability that a continuous randomvariable takes any specific valuea. is equal to zerob. is at least 0.5c. depends on the probability density functiond. is very close to 1.0Max. Score: 136. The z score for the standard normal distributiona. is always equal to zerob. can never be negativec. can be either negative or positived. is always equal to the mean7. A value of 0.5 that is added and/or subtractedfrom a value of x when the continuous normaldistribution is used to approximate the discretebinomial distribution is calleda. 50% of the area under the normal curveb. continuity correction factorc. factor of conversiond. all of the alternatives are correct answers8. Larger values of the standard deviation result ina normal curve that isa. shifted to the rightb. shifted to the leftc. narrower and more peakedd. wider and flatter9. A negative value of Z indicates thata. the number of standard deviations of anobservation is to the right of the meanb. the number of standard deviations of anobservation is to the left of the meanc. a mistake has been made in computations,since Z cannot be negatived. the data has a negative mean10. For the standard normal probability distribution,the area to the left of the mean isa. -0.5b. 0.5c. any value between 0 to 1d. 1Turn the page over for the rest of the quiz .11. Which of the following is not a characteristic ofthe normal probability distribution?a. The mean, median, and the mode are equalb. The mean of the distribution can benegative, zero, or positivec. The distribution is symmetricald. The standard deviation must be 112. In a standard normal distribution, the range ofvalues of z is froma. -3.09 to 3.09b. -1 to 1c. 0 to 1d. minus infinity to infinity13. The probability density function for a uniformdistribution ranging between 2 and 6 isa. 4b. undefinedc. any positive valued. 0.25