In an online survey of 4,001 respondents, 8% were classified as productivity enhancers who are comfortable with technology and use the Internet for its practical value (data extracted from M. Himowitz, "How to Tell What Kind of Tech User You Are," Newsday, May 27, 2007, p F6). Suppose you select a sample of 400 students at your
The U.S. Census Bureau announced that the median sales price of new houses sold in April 2008 was $221,600, and the mean sales price was $274,300 (www.census.gov/newhomesales, July 20, 2009). Assume that the standard deviation of the prices is $90,000.
Let X1, X2, and X3,... be independent identically-distributed Poisson (lamda) random variables. What is the value of P[Xn>n i.o.]? Does it depend on the value of lamda? (Be careful to justify your answer.)
Suppose you are playing Texas holdem and you hold the 8 and 9 of hearts. The flop comes the 3 of hearts, the jack of spades and the Queen of hearts. You now have an inside straight draw (needing a 10 for a straight) and a flush draw (needing a heart for a flush). a) What is the probability that you hit a straight or a flu
According to a report published by the Pew Research Center in February 2010, 61% of Millennial (Americans in their teens and 20's) think that their generation has a unique and distinctive identity (N=527) a. Calculate the 95% confident interval to estimate the percentage of Millennial who believe that their generation has a
You have been research for your statistics class on how nervous the American adults are in general, you have decided to use HINTS 2007 data set that has a scale (going from 0 to 24)measuring the psychological distress of the respondents. a. According to HINTS 2007 data, the average psychological distress score, for this sample
Elizabeth Bailey is the owner and general manager of Princess Brides, which provides a wedding planning service in Southwest Louisiana. She uses radio advertising to market her business. Two types of ads are available--those during prime time hours and those at other times. Each prime time ad costs $390 and reaches 8,200 people,
Suppose you are playing Texas hold'em poker and your two hole cards are the ace of spades and the king of spades. The flop is the two of spades, the seven of spades and the nine of clubs. Find the probability that you will draw a flush by the end of the hand.
Based on Questions tell whether True or False 1. For any normal distribution exactly 97.50% of the z-score values are less than z=1.96. 2. For any normal distribution, the proportion located between the mean and z=1.40 is 0.9192. 3. When determining the probability of selecting a score that is below the mean, you will get a
Suppose there are two types of Penn State Sports fans: Rabid (R), and Casual (R'). These fans either view a big game Live (L) or at Home (L'). Suppose 15% of Penn State fans are both Casual and watch the games at Home. If a fan watches at Home, the probability that he/she is Casual is 80%. Finally, suppose 10% of fans are Rabid.
Given that scores correspond with a raw score of 75.349, any individual with a raw score of 75.349 or higher would be included in your top 25%. If you have 100 scores, will this be the top 25 raw scores do you think? Why or why not?
Find the indicated probability. 1) A bank's loan officer rates applicants for credit. The ratings are normally distributed with a mean of 200 and a standard deviation of 50. If an applicant is randomly selected, find the probability of a rating that is between 170and 220. Solve the problem 2) For women aged 18-24, sy
(a) A student is taking a true-false exam with 20 questions. Assuming that this student guesses at all the 20 questions. (i) Determine the probability that this students gets either fourteen or sixteen answers correct. (ii) Approximate the probability obtained in part (i) by an area under a suitable normal curve. (b) (i) U
When someone buys a ticket for an airline flight, there is a 90% probability that a person will not show up for the flight. Air America books 15 people on a commuter flight that can only seat 13 passengers. What percent of the time will exactly 13 passengers show on time to be seated on the flight? What percent of the time
1. At a college, 70 percent of the students are women and 45 percent of the students receive a grade of C. About 30 percent of the students are female, but not C students. Use this contingency table. (See attached file) If a randomly selected student is male, what is the probability he is a C student? 2. The contingency tabl
A random sample of 20 people found that the number of mail-order catalogs that each had received in the last month were (in order from lowest to highest): 0 0 1 3 5 8 8 9 9 14 17 21 25 29 32 38 43 48 57 62 a) find the range, mean, median, and mode of the data set b) find the sample standard deviation. c) construct a hist
Briefly describe both the statistical measurements of discrete and continuous. Select one level of measurement and explain its relationship with statistical measurement.
Suppose an unfair coin comes up heads 65.2% of the time if it is flipped. If the coin is flipped 14 times, what is the probability that: a) it comes up tails exactly 6 times? b) it comes up heads more than 11 times?
The weekly incomes of a large group of middle managers are normally distributed with a mean of $1,500 and a standard deviation of $150. Use the standard normal distribution to calculate the following: 1. Find the probability that a particular weekly income selected at random is between $750 and $1,500. 2. What is the probabil
Public Private Total Northeast 6 14 20 Mideast 4 12 16 South 15 9 24 West 15 25 40 Total 40 60 100 The following contingency table above cross classifies institution of higher education in the United States by region and type. Suppose an institution of higher educat
A coin was flipped twenty times and landed heads fifteen times. Based upon this information, answer the following the question: If the coin is balanced (fair) what is the probability of a head on the toss? If the coin is not balanced (not fair), what is the probability of a head on the next toss? If a fair coin is flipped t
You are running a blood bank. Every month, a random number of hospital patients will need blood that you will supply. Also, every month, a random number of donors will come in and give blood. You goal is to provide enough blood on hand to supply those patients who need it. At the beginning of the current month you have no pin
In a classical ruin problem with two gamblers, the initial capital of one of the gamblers, Alice, is $90 and the combined initial capital (CIC) is $200. In each trial of the game, an unbiased coin is tossed - Alice wins when the coin shows heads. a) What is the expected duration of the game? b) Given the same CIC, how much
Prob 1. Acceptance sampling is a statistical method used to monitor the quality of purchased parts and components. To ensure the quality of incoming parts, a purchaser or manufacturer normally samples 20 parts and allows 1 defect. a. What is the likelihood of accepting a lot that is 1% defective? b. If the quality of the inco
1) Best Electronics Inc. offers a "no hassle" returns policy. The number of items returned per day follows the normal distribution. The mean number of customers returns is 10.3 per day and the standard deviation is 2.25 per day. a. In what percent of the days are there 8 or fewer customers returning items? b. In what pe
Suppose that the service rate to a waiting line system is 10 customers per hour (exponentially distributed). Analyze how the average waiting time is expected to change as the arrival rate varies from two to ten customers per hour (exponentially distributed).
7.84) Given a binomial random variable with n = 10 and p = .3, use the formula to find the following probabilities. a. P(X = 3) b. P(X = 5) c. P(X = 8) 7.97) In the United States, voters who are neither Democrat nor Republican are called Independents. It is believed that 10% of all voters are Independents. A survey aske
6. A coin is tossed 4 times. Let X denote the number of heads which appear in 4 tosses. a) Construct a probability distribution for X b) Find P(X>2) c) Find the expected value of X d) Find the variance and standard deviation of X 7. The probability that a randomly selected elementary or secondary school teacher from a cit
The solution gives detailed discussion on definitions and calculations of specificity and sensitivity. Some further topics such as positive predictive value, negative predictive value, Lead time bias and length-bias are also explained. All formula of specificity and sensitivity are shown and explained with specific examples.
1) Sensitivity is: A. The probability that a test correctly classifies as positive those who have preclinical disease. B. The probability that a test correctly classifies individuals without preclinical disease as negative C. The probability that those who test positive have the preclinical disease D. The probability that t
The random variable x with probability distribution given below X = 2 3 4 7 10 P(x) = 0.1 0.2 0.4 0.1 0.2 (a) Determine the expected value of x (b) Determine the standard deviation of x (c) Given a sample size of 65, with sample me