Standard Minus
1.The estimate of the population proportion is to be within plus or minus .10, with a 99 percent level of?
confidence. The best estimate of the population proportion is .45. how large a sample is required?
2. Schadek Silkscreen Printing, Inc. Purchases plastic cups on which to print logos for sporting events, proms, birthdays, and other special occasions. Zack Schadek, the owner, received a large shipment this morning. To ensure the quality of the shipment, he selected a random sample of 300 cups. He found 15 to be defective
A.What is the estimated proportion defective in the population?
B.Develop a 95 percent confidence interval for the proportion defective
C.Zack has an agreement with his supplier that he is to return lots that are 10 percent or more defective. Should he return this lot? Explain your decision.
3. A sample of 81 observations is taken from a normal population. The sample mean is 40, and the sample standard deviation is 5. Determine the 95 percent confident interval for the population mean.
The first step for all of these problems is to figure out which probability distribution you're dealing with. Note that for large-sized samples (and large may be as low as 30 observations!), it is usually approximated with a normal distribution.
Then all you need to figure out is the mean and standard deviation (or variance) of this distribution.
When for each observation you have a either/or choice (for a population trait, is it possessed or not), then each one is a Bernouilli(p) distribution. Then the sum over n elements follows a Binomial(n,p), and the mean (or proportion in this case), is this binomial divided by n.
At this point, you can figure out the mean and the standard deviation, get your percentiles and build confidence intervals. Good luck!
 |
 IOMIC Golf Putter Grip Standard Yellow FEEL MINUS ION $17.50 Time Remaining: 1d 12h 30m Buy It Now for only: $17.50 |
 IOMIC Putter Grip Standard Size White Minus Ion iomic $17.50 Time Remaining: 1d 12h 31m Buy It Now for only: $17.50 |
 IOMIC Putter Grip Standard Size Red Minus Ion iomic $17.50 Time Remaining: 1d 12h 31m Buy It Now for only: $17.50 |
 IOMIC Golf Putter Grip Standard Pink FEEL MINUS ION $17.50 Time Remaining: 1d 12h 32m Buy It Now for only: $17.50 |
 IOMIC Golf Putter Grip Standard Orange FEEL MINUS ION $17.50 Time Remaining: 1d 12h 32m Buy It Now for only: $17.50 |
 IOMIC Golf Putter Grip Standard Blue FEEL MINUS ION $17.50 Time Remaining: 17d 21h 4m Buy It Now for only: $17.50 |
 IOMIC Putter Grip Standard Size Mint Green Minus Ion $17.50 Time Remaining: 17d 21h 5m Buy It Now for only: $17.50 |
 Minus Ion Putter Grip IOMIC Standard Size Black Cool $17.50 Time Remaining: 17d 21h 5m Buy It Now for only: $17.50 |
 IOMIC Golf Putter Grip Standard SkyBlue FEEL MINUS ION $17.50 Time Remaining: 17d 21h 5m Buy It Now for only: $17.50 |