Question Suppose the scores of a standardized test are normally distributed. If the population standard deviation is 4 points, what minimum sample size is needed to be 95% confident that the sample mean is within 1 point of the true population mean? ….Kindly click the purchase icon to purchase the full solution at $10
Question Randomly sampled math majors at a large university were asked to take part in a survey about the curriculum. The dean wanted to find out how challenging the math coursework was for students. The proportion of math majors that stated the curriculum was challenging was 0.92, with a margin of error of 0.07. Construct a confidence interval for the…
Question The average length of an eel from a population of short-finned eels is unknown. A random sample from the population yields a sample mean of x¯=1.9 feet. Assume the sampling distribution of the mean has a standard deviation of σx¯=0.6 feet. Use the Empirical Rule to construct a 95% confidence interval for the true population mean length. Provide your answer below:…
Question Suppose an automotive repair company wants to determine the current percentage of customers who keep up with regular vehicle maintenance. How many customers should the company survey in order to be 95% confident that the estimated (sample) proportion is within 4 percentage points of the true population proportion of customers who keep up with regular vehicle maintenance? z0.10…
Question A random sample of SAT scores has a sample mean of x¯=1060 and sample standard deviation of s=195. Use the Empirical Rule to estimate the approximate percentage of SAT scores that are less than 865. Round your answer to the nearest whole number (percent). Provide your answer below: Ans: 16% Question A random sample of CO2 levels in…
Question A normal distribution is observed from the number of points per game for a certain basketball player. If the mean is 16 points and the standard deviation is 2 points, what is the probability that in a randomly selected game, the player scored between 12 and 20 points? Use the empirical rule Ans: 95% Question After collecting the data, Tammy finds that the…
Question A head librarian for a large city is looking at the overdue fees per user system-wide to determine if the library should extend its lending period. The average library user has $19.67 in fees, with a standard deviation of $7.02. The data is normally distributed and a sample of 72 library users is selected at random from the population. Select…
Question The graph below shows the graphs of several normal distributions, labeled A, B, and C, on the same axis. Determine which normal distribution has the largest standard deviation. Ans; c Question Gail averages 64 words per minute on a typing test with a standard deviation of 9.5 words per minute. Suppose Gail’s words per minute on a typing test are normally…
Question The number of miles a motorcycle, X, will travel on one gallon of gasoline is modeled by a normal distribution with mean 44 and standard deviation 5. If Mike starts a journey with one gallon of gasoline in the motorcycle, find the probability that, without refueling, he can travel more than 50 miles. Ans. 0.1151 Question The weights of bags…
Question From recent census data, it is discovered that the proportion of the adults in the United States who are first generation Americans is 14%. For a random sample of size 500, what is standard deviation for the sampling distribution of the sample proportions, rounded to three decimal places? Provide your answer below: Ans. Given the population proportion p=14%=0.14 and…