An Internet retailer stocks a popular electronic toy at a central warehouse that supplies the West Africa sub-region. Every week, the retailer makes a decision about how many units of the toy to stock. Suppose that weekly demand for the toy is approximately normally distributed with a mean of 2500 units and a standard deviation of 300 units. If the retailer has 2750 units on hand at the start of the week, what is the probability that weekly demand will be greater than inventory? A. 0.25 B. 0.797 C. 0.203 D. 0.492 E. 0.874 The Employee Benefit Research Institute reports that 69% of workers reported that they and their spouse had saved some money for retirement. If a random sample of 15 workers is taken, what is the probability that at most all the workers and their spouses have saved some money for retirement? A. 0.2365 B. 0.0356 C. 0.9999 D. 0.3691 E. 0.4871 A random variable is known to be normally distributed with a standard deviation of 0.5. For a an x value of 6.1425, what should be the population mean so that the probability of a value from this distribution exceeding 6.1425 is at most 0.05. A. 5.32 B. 6.02 C. 3.98 D. 4.47 The average stock price for companies making up the GSE is Ghc 30, and the standard deviation is Ghc 8.20. Assume the stock prices are normally distributed. What is the probability a company will have a stock price of at least Ghc 40? A. 0.2451 B. 0.1112 C. 0.3578 D. 0.8888 An Internet retailer stocks a popular electronic toy at a central warehouse that supplies the West Africa sub-region. Every week, the retailer makes a decision about how many units of the toy to stock. Suppose that weekly demand for the toy is approximately normally distributed with a mean of 2500 units and a standard deviation of 300 units. If the retailer has 2750 units on hand at the start of the week, what is the probability that weekly demand will be greater than inventory? A. 0.25 B. 0.797 C. 0.203 D. 0.492 E. 0.874 Quantitative Methods students in UGBS as part of their assignment are taking a survey regarding an SRC presidential hopeful candidate. Of the students sampled, 30% are in favour of the SRC presidential candidate. If 10 people are surveyed, what is the probability that 4 will indicate that they oppose the presidential candidate. A. 0.5127 B. 0.0617 C. 0.0126 D. 0.0367 E. 0.5148 A report issued by the Ghana Statistical service indicates that 65% of all Ghanaians have basic education qualification. Assuming this is true, determine the probability that in a random sample of 20 pedestrians, 2 or fewer will not have a basic education qualification. A. 0.0476 B. 0.0121 C. 0.0525 D. 0.00156 E. 0.5411 Determine the probability of P(x 3) values associated with a Poisson distribution with t equal to 3. A. 0.224 B. 0.149 C. 0.647 D. 0.572 E. 0.711 In a sample size equal to 10 and a probability of a success equal to 0.30, what is the probability that the sample will contain exactly three successes? A. 0.2668 B. 0.3749 C. 0.2361 D. 0.3215 E. 0.5210 Phone calls arrive at the rate of 48 per hour at the reservation desk for Regional Airways. Compute the probability of receiving three calls in a 5-minute interval of time. A. 0.475 B. 0.525 C. 0.652 D. 0.158 In a survey, 300 people were asked to identify their most used social media platform; 180 stated that their most used social media platform was Whatsapp. If an alpha of 0.05 leads to a Z=1.96, the confidence interval for the proportion of people in the population who consider Whatsapp as their major social media platform is? A. C.I=(0.544,0.655) B. C.I=(0.591,0.601) C. C.I=(0.455,0.698) D. C.I=(0.55,0.621) E. C.I=(0.541,0.646) A manager is interested in determining if the population standard deviation has dropped below 130. Based on a sample of n = 20 items selected randomly from the population, what is the critical chi-squared value needed to conduct the appropriate hypothesis test at a 0.05 significance level. The sample standard deviation is 105. A. 13.84 B. 10.117 C. 8.97 D. 15.87 E. 6.44 The Ghana Standard Authority has been approached by Samsung Ghana to test its claim that its new deep freezers yet to be introduced in to the Ghanaian market consumes not more than 150KWh of electricity per year. What is the Type I error in this situation? A. Claiming >150KWh when not true B. Claiming =150KWh when not true C. Claiming 150KWh when not true D. Claiming 150KWh when not true E. Claiming 150KWh when not true The National Quality Research Center provides a quarterly measure of consumer opinions about products and services. A survey of 10 restaurants in the Fast Food/Pizza group showed a sample mean customer satisfaction index of 71. Past data indicate that the population standard deviation of the index has been relatively stable with = 5. Using 95% confidence, what is the margin of error? A. 4.1 B. 5.1 C. 3.1 D. 10.5 E. 2.2 A population has a mean of 400 and a standard deviation of 60. A simple random sample of size 144 is taken to estimate the population mean. What is the standard deviation of the sample mean? A. 0.42 B. 5 C. 6.66 D. 20 E. 60 A recent study on the monthly wages of CEO in companies listed on the Ghana Stock Exchange resulted in a sample mean of GHS155072 out of a sample of 85 CEOs. Given a population mean, =158,972. Determine the sampling error. A. -3900 B. 5000 C. 3900 D. -5000 E. 6000 According to the Business and Financial Times newspaper, through January 25, 2018, majority of companies listed on the Ghana Stock Exchange reporting profits had beaten estimates. A sample of 162 companies showed 104 beat estimates, 29 matched estimates, and 29 fell short. Determine a 95% confidence interval for the proportion that beat their profit estimate. A. CI = (0.120, 0.238) B. CI = (0.247, 0.268) C. CI = (0.568, 0.716) D. CI = (0.487, 0.542) E. CI = (0.687, 0.699) A 95% confidence interval estimate of the population mean annual starting salary of college graduates with degrees in business administration is (GHc30,000, GHc45,000). Assume the sample size for the confidence interval estimate is 25. What is the population standard deviation? A. GHc21,567.5 B. GHc17152.9 C. GHc22,796.4 D. GHc15,889.8 E. GHc19132.7 A paired sample study has been conducted to determine whether two populations have equal means. Twenty paired samples were obtained with the following sample results: Mean of deviations (dbar)=12.45; Standard deviation of the deviations (Sd) =11.0. A 90% confidence interval estimate for the pair difference in mean values will be A. CI = (4.4, 8.8) B. CI = (6.8, 12.45) C. CI = (8.4, 16.5) D. CI = (10.5, 13.4) E. CI = (16.45, 18.45) In a survey, 300 people were asked to identify their most used social media platform; 180 stated that their most used social media platform was Whatsapp. If an alpha of 0.05 leads to a Z=1.96, the confidence interval for the proportion of people in the population who consider Whatsapp as their major social media platform is? A. C.I=(0.544,0.655) B. C.I=(0.591,0.601) C. C.I=(0.455,0.698) D. C.I=(0.55,0.621) E. C.I=(0.541,0.646) In a survey, 300 people were asked to identify their most used social media platform; 180 stated that their most used social media platform was Whatsapp. If an alpha of 0.05 leads to a Z=1.96, the confidence interval for the proportion of people in the population who consider Whatsapp as their major social media platform is? A. C.I=(0.544,0.655) B. C.I=(0.591,0.601) C. C.I=(0.455,0.698) D. C.I=(0.55,0.621) E. C.I=(0.541,0.646) A manager is interested in determining if the population standard deviation has dropped below 130. Based on a sample of n = 20 items selected randomly from the population, what is the critical chi-squared value needed to conduct the appropriate hypothesis test at a 0.05 significance level. The sample standard deviation is 105. A. 13.84 B. 10.117 C. 8.97 D. 15.87 E. 6.44 A test of hypothesis has the following hypotheses: H0:p0.4 Ha:p>0.4 Calculate the numerical value of the test statistic for a sample of size of 40, and a sample proportion of 0.5. A. 0.1291 B. 0.548 C. 2.450 D. 0.985 E. 0.998 A simple random sample with n = 54 provided a sample mean of 22.5 and a sample standard deviation of 4.4. Develop a 90% confidence interval for the population mean. A. 20.9 to 24.1 B. 21.3 to 23.7 C. 21.5 to 23.5 D. 20.7 to 24.4 E. 19.8 to 23.3 The National Quality Research Center provides a quarterly measure of consumer opinions about products and services. A survey of 10 restaurants in the Fast Food/Pizza group showed a sample mean customer satisfaction index of 71. Past data indicate that the population standard deviation of the index has been relatively stable with = 5. Using 95% confidence, what is the margin of error? A. 4.1 B. 5.1 C. 3.1 D. 10.5 E. 2.2