Quantitative Methods Mid term Question 1 Deterministic techniques assume that no uncertainty exists in model parameters. Selected Answer: True Question 2 An inspector correctly identifies defective products 90% of the time. For the next 10 products, the probability that he makes fewer than 2 incorrect inspections is 0.736. Selected Answer: True Question 3 A joint probability is the probability that two or more events that are mutually exclusive can occur simultaneously. Selected Answer: False Question 4 A decision tree is a diagram consisting of circles decision nodes, square probability nodes, and branches.
1) Which of the following measures of central location is affected most by extreme values? A. Median B. Geometric mean C. Mean D. Mode Ans : C 2) A difference between calculating the sample mean and the population mean is: A. Only in the symbols, we use x instead of µ and n instead of N. B. There are no differences.
A Shapiro-Wilk test on the transformed data provides no evidence against the transformed data having come fro a normal distribution (P-value=0.4286). Statistical Inference We can estimate both the population mean and median incomes. The P-values from the t-tests are not sensible here: Executive Summary Our interest in these data was to estimate both the mean and median lifetime (in hours) of light bulbs in a warehouse. We estimate that the mean family income is between 1083 and 1122 hours, while the median family income is between 1074 and 1112
According to the Central Limit Theorem, it will be bell shaped because it is normally distributed. We should not make any assumptions because the sample size is larger than 30 which conclude that all possible sample means are approximately normally distributed. Find the mean and the standard deviation of the sampling distribution of the sample mean x bar. Mean = 1/n x n x mean (x_1) = 20 Mean of sample means = 20 Standard deviation = x/n = 4⁄8= ½ Standard deviation of the sample means = ½ Calculate the probability that we will obtain a sample mean greater than 21; that is, calculate P(x bar>21). Hint: Find the z value corresponding to 21 by using μ_(x bar) and σ_(x bar) because we wish to calculate a probability about x bar.
2. Compute the skip interval by dividing the total number of names in the list by the sample size: Skip interval = 250/10 = every 25th name in the list 3. Use random numbers to determine the first number that must be the start of the sampling list. The table of random numbers is a listing that is basically generated electronically (from 001 to 250) where no duplication of number is ensured. If from the randomly listed numbers, 9 was selected (or picked), the first sample is passenger number 009.
Suppose a student in Business Statistics has no been attending class this quarter but decides to take the exam anyway. If he randomly guesses on each of the 20 questions, then he has a 1 out of 5 chance of getting a correct answer, since it is multiple choice exam with choices a, b, c, d, or e. 8) How many questions should the student expect to get correct on this exam? 9) What is the probability that the student will get a “C” or better, which is 14 or more correct? 10) What is the probability that the student will score lower than a “C” (13 or less correct)? Use the following scenario to answer the next 5 questions.
We are doing a survey on various aspects of college life. It takes about 5-10 minutes and is completely anonymous. I'd really appreciate it if you would take part. The link to the survey is (http://www.surveymonkey.com/s/LMF63QJ) and it should be self-explanatory. Thanks!
Answer: C A nondiscriminating pure monopolist's demand curve: A) is perfectly inelastic. C) lies above its marginal revenue curve. B) coincides with its marginal revenue curve. D) lies below its marginal revenue curve. Answer: C For an imperfectly competitive firm: A) total revenue is a straight, upsloping line because a firm's sales are independent of product price.
The consumers are risk-neutral: if they have probability p of getting a high quality product, they value this prospect 14p + 8(1 - p) Each type of manufacturer can produce the product at a constant unit cost of 11. a) Suppose that the sale of low quality calculators is illegal, so that the only items allowed to appear on the market are of high quality. What will be the equilibrium price? b) Suppose that there are no high quality sellers. How many low quality calculators would you expect to be sold in equilibrium? c) Could there be an equilibrium in which equal (positive) quantities of the two types of calculators appear in the market?
Therefore the sample should not be stratified based on this grouping. 2. The proportion of people satisfied with the service quality can be represented by the following equation: p ̃=(X+2)/(n+4) = 91/136 = 0.6691 = 67% Satisfaction Frequency Percent Valid Percent Cumulative Percent Valid Satisfie 89 67.4 67.4 67.4 Unsatisf 43 32.6 32.6 100.0 Total 132 100.0 100.0 Bound: p ̃±2√(var(p ̃)) NOTE: FPC is not required as the sample number (132) is less than 10% of the population number (approximately 40,000). p ̃±2√((p ̃(1-p ̃))/(n+4)) p ̃±2√((0.6691(1-0.6691))/136) B =