A study found that 6.7% of working Americans have worked at Mcdonalds. Let X represent the number of working Americans in a random sample of 900 Americans, who have worked at Mcdonalds. Find the mean and the standard deviation of X In a random sample of 900 working Americans, would it be unusual to find 65 of them have worked at Mcdonalds? Justify your answered
A study found that 6.7% of working Americans have worked at Mcdonalds. Let X represent the number of working Americans i...
radley Corporation conducted a study of adult Americans and found out that 64%)of them used their foot to operate the flusher in public restrooms. A survey of a random sample of20 adult Americans about using their foot to flush. Find a) the mean number adult Americans who uses their foot b) the variance of adult Americans who uses their foot c) the standard deviation of adult Americans who who uses their foot the probability that d) exactly 12 used their...
8. Let the random variable x represent the number of girls in a family with three children. Assume the probability of a child being a girl is 0.35 The table on the right describes the probability of having x number of girls. Determine whether the table describes a probability distribution. If it does, find the mean and standard deviation. Is it unusual for a family of three children to consist of three girls? x P(x) 0 0.275 1 0.444 2 ...
3. Binomial Distribution. Are Americans superstitious? A Harris (Feb. 2013) poll of over 2,000 adult Americans was designed to answer this question. One survey item concerned the phrase “see a penny, pick it up, all day long you’ll have good luck.” The poll found that about 30 percent of Americans believe finding and picking up a penny is good luck. Consider a random sample of 20 U.S. adults and let x represent the number who believe finding and picking up...
Researchers believe that 70% of all Americans believe in God. Let X equal the number of people that believe in God out of 40 Americans. Find the mean and standard deviation of X.
A recent research study reported that Americans spend an average of 3.6 hours on social media - per person per day. If the standard deviation for the number of hours of social media per day is 3 and a random sample of 145 Americans is selected for further study, answer the following questions about the sampling distribution: 1) The mean of this sample of n=145 belongs to a sampling distribution. What is the shape of this sampling distribution? 2) What...
Let the random variable x represent the number of girls in a family with three children. Assume the probability of a child being a girl is 0.31. The table on the right describes the probability of having x number of girls. Determine whether the table describes a probability distribution. If it does, find the mean and standard deviation. Is it unusual for a family of three children to consist of three girls? 0 1 2 3 P(x) 0.329 0.443 0.199...
A population has a mean of 150 and a standard deviation of 30. Let X-bar represent the sample mean used to estimate the population mean. If the size of the random sample is 25, find the probability that X-bar > 160.
Let X represent the full height of a certain species of tree. Assume that X has a normal probability distribution with mean 196.5 ft and standard deviation 65 ft. You intend to measure a random sample of n = 229 trees. The bell curve below represents the distibution of these sample means. The scale on the horizontal axis is the standard error of the sampling distribution Complete the indicate boxes, correct to two decimal places.
conducts an experiment in which they tip a coin 10 times and count of heads. Let the random represent varlable X represent the number of heads. Write the distribution of x In a class of 40 students, each student conducts an experiment in which they flip a coin 10 times and count the number of heads. Let the random variable&represent the mean number of heads found by the students Write the distribution of á 8) One student conducts an experiment...