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A machine which produces a major part for an airplane engine is monitored closely. In the past, 10% of the parts produced are defective. With a 95% confidence, what is the the sample size that needs to be taken if the desired sampling error is 5% or less. Round appropriately.

The scores on a college entrance exam have an approximate normal distribution with mean, µ = 52 points and a standard deviation, σ = 11 points. Find the following using the empirical rule. About 68% of the y values lie between [a1] points and [a2] points.  

Identify the null hypothesis H0 and the alternative hypothesis HA. Use μ for a claim about a mean and p for a claim about a proportion.A cereal company claims that the mean weight of the cereal in its packets is at least 14 oz.

Use the confidence level and sample data to find the margin of error, E, for the mean. 95% confidence, n = 8, sample mean = 38.0, and s = 9.7 (Assume the data has a normal distribution.)

Solve the problem. Find the critical value that corresponds to a degree of confidence of 91%.

Find the indicated probability. The following table contains data from a study of two airlines which fly to Small Town, USA. If one of the 87 flights is randomly selected, find the probability that the flight selected arrived on time AND was on the Upstate Airlines.  

Use the margin of error, confidence level, and standard deviation,

Find the indicated probability. Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. A vending machine will only accept coins weighing between 5.48 g and 5.82 g. What percentage of legal quarters will be rejected?

Original claim:  The mean pulse rate (in beats per minute) of a certain group of adult males is 73 bpm. The hypothesis test results in a p-value of 0.0096. Assume a significance level of α = 0.01. State a conclusion about the null hypothesis.  

X ~ N(4, 5) Find the maximum of x in the bottom quartile. (Round to 2 decimal places as needed.)