Question A survey asked recently retired people the number of people, X, they met through work during their working lives that they considered close friends. The table below is a probability distribution table representing the data collected. Find the mean and the standard deviation of the probability distribution using Excel. Round the mean and standard deviation to three decimal places.   Question A study randomly selected 100 samples, each of which consisted of 100 people, and re...

Question On average, Ruth has noticed that 20 trains pass by her house daily (24 hours) on the nearby train tracks. What is the probability that at most 5 trains will pass her house in a 7 hour time period? Round the final answer to three decimal places. Answer:  Question Stephanie gets an average of 11 calls during her 8 hour work day. What is the probability that Stephanie will get more than 4 calls in a 2 hour portion of her work day? (Round your answer to three decimal place...

Question 65% of the people in Missouri pass the driver’s test on the first attempt. A group of 5 people took the test. What is the probability that less than 3 in the group pass their driver's tests in their first attempt? Round your answer to three decimal places. Remember: 65% = 0.65.   Question A softball pitcher has a 0.431 probability of throwing a strike for each pitch. If the softball pitcher throws 22 pitches, what is the probability that exactly 12 of them are strike...

Question A random sample of high school students were surveyed about technological devices. They were asked, “How many computers do you have in your household?”  The table below represents the probability density function for the random variable X, the number of computers per household. Find the standard deviation of X. Round the final answer to two decimal places. x  P(X = x) 3  1/4 4  1/4 7  1/2   Question Which of the following tables show...

Question The speed (in mph) of randomly selected bicyclists were measured as they were approaching a hill.  The results are presented in the following histogram. How many of those bicyclists were traveling greater than 8.5 but less than 11.5 mph as they were approaching the hill?   Question Several people were asked to report the number of hours of sleep they average per night.  The results are shown in the histogram below.  How many of those people average greater than 4.5 b...

Question A group of students were surveyed about the number of times they went to a movie theater last year. Their responses are summarized in the relative frequency table below. What is the cumulative relative frequency of students that went to 7 or fewer movies? Number of Movies Relative Frequency 0−1 0.08 2−3 0.20 4−5 0.30 6−7 0.24 8−9 0.10 10 or more 0.08   Question A small startup company wishes to know how many hours, per week...

Question At a carnival, contestants are asked to keep rolling a pair of dice until they roll snake eyes.  The number of rolls needed has a mean of 36 rolls, with a standard deviation of 5.4 rolls. The distribution of the number of rolls needed is not assumed to be symmetric. Between what two numbers of rolls does Chebyshev's Theorem guarantee that we will find at least 75% of the contestants? Round your answers to the nearest tenth. Enter the bounds in ascending order. Question Accord...

Question Based on the z-scores calculated above for Stephan's electric bills in IL and FL, in which state is his electric bill higher, when compared to their respective distributions? Question When Stephan moved from Illinois to Florida, his average monthly electric bill increased from $83 to $102.  He is curious to know whether his IL or FL electric bill is relatively more or less expensive, when compared to the distribution of electric bills for each state. In Illinois, the mean monthly e...

Question In a study to add a new feature to a software program, the programmer introduced two categories, men and women, in the survey she conducted. Is the study observational or experimental? If it is an experiment, what is the controlled factor? Question A biology student is interested in the relationship between temperature and germination time for soy beans. The student gets sample seeds from multiple sources and randomly selects 180 seeds from them. Then he sets up three growing stati...

Question The following data represents the inches of rainfall y  in month x of the year in a city in the U.S. (1 is January, 2 is February, etc.) Using a calculator or statistical software, find the linear regression line for the data in the table. Enter your answer in the form y=mx+b, with m and b both rounded to two decimal places. x  y 1 3.53 2 4.93 3 1.58 4 2.72 5 4.68 6 3.34   Question Using a calculator or statistical s...