Pitt MATH 1100 - Exam
Pages 31

Unformatted text preview:

What type of graph depicts the data below? ANS: Line chartWhat proportion of the data from a normal distribution is within two standard deviations from the mean? 0.9544What number corresponds to t0.05,10? 1.812What number corresponds to ? 21.00What number corresponds to F0.95,4,8? 0.166What number corresponds to F.025,3,5? 7.76What does the length of each line of a stem-and-leaf display represent? ANS: The number of observations in the interval represented by that stem.What values are displayed on a cumulative relative frequency distribution? ANS: The proportion of observations that fall below each class intervalValues must represent ordered rankings for what type of data? ANS: Ordinal data. 2.1How do confidence levels compare to significance levels? ANS: Confidence levels are typically large and significant levels are typically small. Given the least squares regression line , and a coefficient of determination of 0.81, the coefficient of correlation is: 0.90Given the least squares regression line , and a coefficient of determination of 0.81, the coefficient of correlation is: 0.90 Given that Z is a standard normal random variable, the area to the left of a value z is expressed as P ( Z  z ) Given that Z is a standard normal variable, the variance of Z: is always equal to 1.0.Given a Poisson random variable X, where the average number of successes occurring in a specified interval is 1.8, then P(X = 0) is:0.1653Given the information: the number of degrees of freedom that should be used in the pooled variance t-test is:38Given that X is a binomial random variable with very large n, the binomial probability P(X  5) is approximated by the area under a normal curve to the right of4.5Given that X is a binomial random variable with very large n, the binomial probability P(X  5) is approximated by the area under a normal curve to the left of5.5Given that Z is a standard normal variable, the variance of Z: is always equal to 1.0.Given that Z is a standard normal random variable, a negative value (z) on its distribution would indicate: z is to the left of the mean. Generally speaking, if two variables are unrelated (as one increases, the other shows no pattern), the covariance will be: A positive or negative number close to zero.Using a confidence interval when conducting a two-tail test for , we do not reject H0 if the hypothesized value for :falls between the LCL and UCL.Under what condition(s) does the test statistic for p have an approximate normal distribution?When np and n (1  p ) are both > 5.We have created a 95% confidence interval for  with the result (8, 13). What conclusion will we make if we test H0:   15 vs. H1:   15 at  = 0.05?Reject H 0 in favor of H 1We have created a 95% confidence interval for  with the results (10, 25). What conclusion will we make if we test H0:   26 vs. H1:   26 at  = 0.025 ?We cannot tell from the information given.We have created a 90% confidence interval for  with the result (25, 32). What conclusion will we make if we test H0:   28 vs. H1:   28 at  = 0.10 ?Fail to reject H 0 in favor of H 1.We cannot commit a Type I error when the:null hypothesis is false.TRUE/FALSE A grocery store's monthly sales (in thousands of dollars) for the last year were as follows. A histogram should be used to present these data. ANS: FALSETRUE/FALSE Time series data are often graphically depicted on aline chart, which is a plot of the variable of interest over time. ANS: TRUETRUE/FALSE A line chart is created by plotting the values of the variable on the vertical axis and the time periods on the horizontal axis. ANS: TRUETRUE/FALSE The graph below represents a line graph. FALSETRUE/FALSE The line chart below shows pepper prices each month from January (month 1) to December last year (\$ per pound). By looking at this chart you can see the lowest pepper prices occurred in July. TRUEMonth 1 2 3 4 5 6 7 8 9 10 11 12Sales 78 74 83 87 85 93 100 105 103 89 78 94TRUE/FALSE The line chart below shows pepper prices fluctuated from \$2.00 per pound to over \$4.50 per pound during the year. TRUETRUE/FALSE A line chart that is flat shows no fluctuation in the variable being presented. TRUEThe value for a 95% confidence interval estimate for a population mean  is1.96The average score for a class of 30 students was 75. The 20 male students in the class averaged 70. The 10 female students in the class averaged: 85The bar charts below summarize data collected on 100 adults regarding gender and pet ownership. Which of the following statements is (are) true based on this chart? Gender and pet ownership are related, a higher percentage of females own pets than males.The critical values z or z / 2 are the boundary values for:the rejection region(s)The collection of all possible outcomes of an experiment is called: SAMPLE SPACEThe collection of all possible events is called A SAMPLE SPACEThe confidence level of a statistical inference measures: ANS: The proportion of times an estimation procedure will be correct in the long run. The classification of student major (accounting, economics, management, marketing, other) is an example of a(n): ANS: Nominal random variable 2.1The classification of student class designation (freshman, sophomore, junior, senior) is an example of a(n) ANS: Ordinal Random variable 2.1The confidence interval estimate of the expected value of y for a given value x, compared to the prediction interval of y for the same given value of x and confidence level, will be:narrower.The covariance of two variables X and Y: can be any real number.The difference between a sample mean and the population mean is called: SAMPLING ERRORThe denominator in the calculation of the sample covariance, cov (x,y), is: n-1The Dean of Students from a large university mailed a survey to 500 students selected at random. The sample was designed to include 125 students randomly selected from each of the freshman, sophomore, junior, and senior classes on campus. What sampling method wasused? STRATIFIED RANDOM SAMPLEThe expected value, E(X), of a binomial probability distribution with n trials and probability p of success is:npThe expected number of heads in 100 tosses of an unbiased coin is 75The exponential density function f(x):approaches zero as x approaches infinity. The expected value of the sampling distribution of the

View Full Document

# Pitt MATH 1100 - Exam

Pages: 31
Documents in this Course

36 pages

18 pages

2 pages

12 pages

2 pages

2 pages

Load more
Download Exam
Our administrator received your request to download this document. We will send you the file to your email shortly.
Unlocking...
Sign Up

Join to view Exam 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?