Consumer Reports rated airlines and found that 79% of the flights involved in the study arrived on time (i.e., within 15 minutes of scheduled arrival time). Assuming that the on-time arrival rate is representative of the entire commercial airline industry, consider a random sample of 197 flights. (Round your answers to two decimal places.) What is the expected number that will arrive on time? What is the standard deviation of this distribution?

Consumer Reports rated airlines and found that 79% of the flights involved in the study arrived on time (i.e., within 15 minutes of scheduled arrival time). Assuming that the on-time arrival rate is representative of the entire commercial airline industry, consider a random sample of 197 flights. (Round your answers to two decimal places.) What is the expected number that will arrive on time? What is the standard deviation of this distribution?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

Business Weekly conducted a survey of graduates from several top MBA programs. On the basis of the survey, assume the mean annual salary for graduates 10 years after graduation is $124,000. Assume the standard deviation is $42,000. Suppose you take a simple random sample of 17 graduates. Round all answers to four decimal places if necessary What is the standard deviation of ¯¯¯XX¯? For a single randomly selected graduate, find the probability that her salary is between $111,920 and $125,213. For a simple random sample of 17 graduates, find the probability that the average salary is between $111,920 and $125,213.
A developmental psychologist is interested in studying how long babies gaze at a photograph of a human face. To test this question, she shows a picture to a sample of six babies and records the length of their gaze in seconds. The data are as follows: 12, 17, 18, 20, 20, 29. Calculate the mean, median, mode, range, variance and standard deviation for the sample.
A store manager claims that the mean amount of time customers spend waiting in line is less than the 3.7 minutes. You wish to test this claim. The mean waiting time for a random sample of 85 customers is 3.3 minutes with a standard deviation of 0.8 minutes. What is the test statistic? -0.50 O 1.645 -4.61 4.61
Business Weekly conducted a survey of graduates from several top MBA programs. On the basis of the survey, assume the mean annual salary for graduates 10 years after graduation is $185,000. Assume the standard deviation is $40,000. Suppose you take a simple random sample of 22 graduates. Round all answers to four decimal places if necessary. What is the standard deviation of distribution of X? 185,000 • What is the standard deviation of X? 40,000 • For a single randomly selected graduate, find the probability that her salary is between $175,608 and $186,672. 0.1070 • For a simple random sample of 22 graduates, find the probability that the average salary is between $175,608 and $186,672. 0.0912 For part d), is the assumption of normal necessary? O NoO Yes
n a school district, all sixth grade students take the same standardized test. The superintendant of the school district takes a random sample of 21 scores from all of the students who took the test. She sees that the mean score is 128 with a standard deviation of 41.4416. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 25. Is there evidence that the standard deviation of test scores has increased at the α=0.005 level? Assume the population is normally distributed. Step 1 of 5 : State the null and alternative hypotheses. Round to four decimal places when necessary.
Esp Heavy children: Are children heavier now than they were in the past? The National Health and Nutrition Examination Survey (NHANES) taken between 1999 and 2002 reported that the mean weight of six-year-old girls in the United States was 49.3 pounds. Another NHANES survey, published in 2008, reported that a sample of 193 six-year-old girls weighed between 2003 and 2006 had an average weight of 52 pounds. Assume the population standard deviation is o =16 pounds. Can you conclude that the mean weight of six-year-old girls in 2006 is different from what it was in 2002? Use the a =0.01 level of significance and the critical value method. 00 Part: 0/ 5 Part 1 of 5 (a) State the appropriate null and alternate hypotheses. H.: OD O=0 dl. H : This hypothesis test is a (Choose one) test. 00
Business Weekly conducted a survey of graduates from 30 top MBA programs. On the basis of the survey, assume the mean annual salary for graduates 10 years after graduation is $136,000. Assume the standard deviation is $39,000. Suppose you take a simple random sample of 9 graduates. Round all answers to four decimal places if necessary.
In a local university, 80% of the students live in the dormitories. A random sample of 64 students is selected for a particular study. The standard deviation of p-bar is a. 64 b. 0.05 c. 1.6 d. 0.16 e. 0.5
A survey finds that the prices paid for two-year-old Ford Fusion cars are normally distributed with a mean of $17,500.00 and a standard deviation of $500.00. Consider a sample of 10,000 people who bought two-year-old Ford Fusions. 6800 of the people who bought two-year old Ford Fusions spends between $ .00 and $ .00 How many people spends less than $17,000.00 people. How many people spends more than $19,000.00 people (Note this question has to do with the empirical rule and the symmetric nature of the normal distribution)
In a certain population, let us assume that high school scores are normally distributed with mean of 74 and standard deviation of 15. What is the 75th percentile? Select one: O a. 84.05 O b. 68.15 O c. 79.85 O d. 63.95
The salary of a recent graduate from a northeast university with an MBA follows a normal distribution with a mean starting salary of $78,000 with a standard deviation of $15,000. You apply the normal model and discover that approximately 7.1% receive a starting salary of more than $100,000. A university administrator surveyed a random sample of 450 of their recent graduates that earned an MBA. How many of these graduates would you expect to receive a starting salary of more than $100,000? Explain.
The annual income of residents in a county is $42,000, with a standard deviation of $10,000. (b) What is the percentage that a randomly chosen resident has an income of less than $22,000?