A simple random sample of 20 commuters to the Los Angeles metropolitan area are selected, and each is asked how far they commute to work each day.  In the sample, the mean distance is 64 miles and the standard deviation is 12 miles.  Assume that in the population of all commuters to the Los Angeles metropolitan area, daily commuting distance follows a normal distribution, with some mean \muμ.    What is the standard error for \bar xxˉ in this sample? Give your answer to two decimal places

Assume that scores on a bone mineral desity test are normally distributed with a mean of 0 and a standard deviation of 1.    b. what do the symbols mean^2 and standard deviation ^2 represent.

A single serving bag of Ray's Classic Potato Chips is listed on the package to be 28.3 grams. The manufacturing process for potato chips can vary from bag to bag. The listed weight of the bag of potato chips is the average weight. The weight of a bag of Ray's chips is known to be Normally distributed with a standard deviation of 0.4 grams. Ray's Potato Chips will not sell any bags that are in bottom 4% of all weights. Find the maximum value that would put a randomly selected bag of Ray's chips at the 4th percentile of weights. O a. 27.6 grams O b.27.24 grams O. 28.2 grams O d.29.0 grams

An opinion poll asks a simple random sample of   1500 adults how they view the state of the economy.  Suppose that  73% of all adults would say "good" if they were asked.  In repeated samples, the sample proportion p^ who say "good" would follow a normal distribution with mean having a value of

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The time for an event for girls in secondary school is known to posses a normal distribution within a mean of 450 seconds and a standard deviation of 50 seconds.  Find the probablity that a randomly selected girl in a secondary school will take longer 335 seconds to run the mile

The Credit Risk Department of a major bank estimates the default rate on loans under $10,000 to be 4%. The bank will make 2400 loans that are under $10,000 next month.  Find the mean of ^p, where ^p is the proportion of defaults on the 2400 loans under $10,000 to be made next month.

MSNBC recently reported that the mean annual cost of auto insurance is 966 dollars. Assume the standard deviation is 275 dollars. You take a simple random sample of 94 auto insurance policies. Find the probability that a single randomly selected value exceeds 962 dollars.   = Incorrect0.5058 Find the probability that a sample of size is randomly selected with a mean that exceeds 962 dollars.   = Correct Enter your answers as numbers accurate to 4 decimal places.

A highly selective boarding school will only admit students who place at least 2 standard deviations above the mean on a standardized test that has a mean of 300 and a standard deviation of 24 What is the minimum score that an applicant must make on the test to be accepted? The minimum score that an applicant must make on the test to be accepted is

An old medical textbook states that the mean sodium level for healthy adults is 138mEq per liter of blood. A medical researcher believes that, because of modern dietary habits, the mean sodium level for healthy adults, μ, now differs from that given in the textbook. A random sample of 60 healthy adults is evaluated. The mean sodium level for the sample is 142mEqper liter of blood. It is known that the population standard deviation of adult sodium levels is13 mEq. Can we conclude, at the 0.05 level of significance, that the population mean adult sodium level differs from that given in the textbook? Perform a two-tailed test. Then complete the parts below.Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (For z test statistics) every expert has gotten the z test statistic wrong thus far. I have included pictures of a sample problem and formula. A. State the null hypothesis H0 and…