Quiz 5

Quiz 5 Your work has been saved and submitted Written Feb 13, 2024 6:47 PM - Feb 13, 2024 9:21 PMAttempt 1 of 1 Attempt Score 94 / 100 - 94 % Overall Grade (Highest Attempt) 94 / 100 - 94 % Question 1 8 / 8 points Match terms and descriptions __5 __ Convenience Sampling __2 __ Standard Deviation __8 __ Biased Statistic __4 __ Random Sampling __7 __ Biased Sample __1 __ Unbiased Sample __6 __ Sampling Error __3 __ Standard Error 1 . A sample that is representative of a population 2 . Value quantifying the spread about the mean of numeric values 3 . The standard deviation of a distribution of statistics resulting from sampling or an estimate of the standard deviation 4 . A method of sampling where each member of the population is equally likely to be included in a sample 5 . A method of sampling where easily accessible members of a population are sampled 6 . The difference between observations in a sample and observations in the population 7 . A sample obtained by a non-random sampling method 8 . The mean of a distribution of statistics is not equal to the parameter the statistic estimates Question 2 2 / 2 points Sampling error can be eliminated by: Performing a census Obtaining an unbiased sample Using a probability sampling method Increasing sample size

Hide question 2 feedback The difference between the sample and the sampling population is called sampling error. A census is equal to a population. So, there is no difference and no sampling error. Question 3 4 / 4 points Select all which are biased sampling methods With each group composed of people with the same characteristic and each person belonging to only one group, a random sample is taken from each group. Survey the first 20 people entering a particular coffee store on the last Tuesday before the next election Survey two union workers for each non-union worker Telephone survey Groups are selected by random sampling. People in the selected groups are surveyed. Hide question 3 feedback Each member of the population does not have an equal chance of being samples. This is called a convenience sample. Each member of the population does not have an equal chance of being samples. This sampled is biased to the union. Each member of the population does not have an equal chance of being samples. Question 4 5 / 5 points Match __1 __ Probability Sampling Methods __3 __ Systematic Random Sampling __2 __ Simple Random Sampling __5 __ Stratified Random Sampling __4 __ Cluster Random Sampling 1 .      Each member of the population has an equal chance of being selected for a sample. 2 .      Each member of the population is assigned a unique number. Randomly select numbers from a list of assigned numbers. 3 .      Each member of the population is assigned a unique number. The first number is selected randomly. The remaining numbers are selected at equal intervals. 4 .      The population is divided into separate physical units. Each member of the population belongs to only one physical unit. Physical units are selected by simple random sampling. In each

random variable, mean, standard deviation, and additional input 1 (0=height of curve, 1=area under curve). 5 .      Compute the value of a normal random variable from a left- tail probability, mean, and standard deviation. Question 8 2 / 2 points The probability distribution of the means of large samples taken from the same probability distribution will be approximately Normal regardless of the distribution the sample was taken from. This is called the Normal Distribution Theorem Central Limit Theorem Law of Large Numbers Law of Large Sample Size Law of Averages Questio n 9 4 / 4 points Select the true statements. Distributions of sample means become approximately normally distributed when sample size is at least 50 for highly skewed populations. Distributions of sample means are approximately normally distributed because the sample mean estimates the population mean. Distributions of sample means become approximately normally distributed when sample size is at least 30 for most populations. Hide question 9 feedback FYI, distributions of sample means become approximately normally distributed when sample size is at least 10 for symmetrical populations. Question 10 4 / 4 points Match formulas __2 __ Sample Standard Deviation __3 __ Estimated Standard Error of Sample Means __1 __ Sample Mean 1 . 2 .

__4 __ Estimated Standard Error of Sample Proportions using sample proportion p as estimate of the population proportion 3 . 4 . Question 11 6 / 6 points According to the Empirical Rule what percent of the population is within 2 standard deviations from the mean? None of the answers match my calculation. 5% 32% 95% 99.7% 68% 0.3% Hide question 11 feedback Question 12 6 / 6 points According to the Empirical Rule what percent of the population is above 1 standard deviation above the mean, which is a right-tail probability? 81.5% None of the answers match my calculation. 16% 83.85% 2.5% 0.15%

Hide question 14 feedback The upper Z limit for the given middle probability is = NORM.S.INV(0.5 + 0.27/2). The lower Z limit is the negative of the upper Z limit because of the symmetry of the standard normal distribution about 0. Question 15 6 / 6 points If the mean annual return for common stocks is 10.0% and the standard deviation 12.0%, what is the probability that the stock returns are less than 7%? 15% 40% 0% 58% 53% None of the answers match my calculation. 47% Hide question 15 feedback =NORM.DIST(7, 10, 12, 1) Question 16 6 / 6 points The distribution of a product is unimodal and roughly symmetric. The package is labeled 10 oz. If the standard deviation is 0.2 ounces, what should the process mean be if 2% of the product is underweight? 13.41 14.38 15.35 12.35 None of the answers match my calculation. 11.38 10.41 Hide question 16 feedback Population mean = label weight-(Zscore x SD). =10-NORM.S.INV(0.02)*0.2

Question 17 0 / 6 points If the mean annual return for a stock is 14%, what is the risk (standard deviation) you would take for a probability of 32% of a return being at least 19%? 8% 11% 6% 17% None of the answers match my calculation. 14% 21% Hide question 17 feedback =(19-14)/NORM.S.INV(1-0.32) Question 18 6 / 6 points The Chunkiest cookie factory changed their manufacturing process. The inspectors sampled 70 12.0-oz packages with mean 12.03 oz and a standard deviation of 1.5 oz. The CEO asks what is the upper weight boundary of the middle 55% of package weights. 13.16 12.1 10.64 14.69 None of the answers match my calculation. 9.87 8.82 Hide question 18 feedback =NORM.INV(0.5+0.5*0.55,12.03,1.5) Question 19 6 / 6 points If the sample standard deviation is 7.36, what would be the estimated standard error of sample means for sample size 15? Write the result with 2 decimal places. Answer: