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The following output is the result of running a linear regression on WEIGHT (y) = average weight in pounds for American females between 30 and 39 years, and HEIGHT (x) = height in inches.
A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that the sample mean will be between 297 to 303 is ??
If a sample of 100 is taken, and 9 of these are found to be defective, should the process be considered out of control? Explain.
Based on the result in a), what type of error could possibly occur? Explain the effect of this error to the cake house.
A poll reported that 65% of adults were satisfied with the job the major airlines were doing. Suppose 12 adults are selected at random and the number who are satisfied is recorded. (a)Find the proba
At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus teams in the National League?
How many different sets of exactly 20 of the 23 people with reservations for coach seats are possible? (do you use permutations or combinations?) b. How many different sets of more than 20 of the 23
The J.O. supplies company buys calculators the probability of a defective calculator is 10%. If 100 calculators are selected at random, what is the expected number of defective?
Assume that the average annual salary for a worker in the United States is $31,000 and that the annual salaries for Americans are normally distributed with a standard deviation equal to $7,500. Find
The ACT is also distributed with meanof 21 and standard deviation of 4.7. Rachel wants to be in the 98th percentile on each test. What scores must she recieve on each exam?
The composite ACT scores of entering freshmen at an area University have a N(24,4) distribution. Use this information to complete the following.
Range of numbers: What is the first and third quartile?
The population standard deviation of 54.2 days. Estimate the true mean population of the growing season with a 95% confidence.
One of the many concerns of college students today is the time required for them to graduate with a baccalaureate degree (BA or BS). compute the value of the test statistic t*.
Eight pairs of data yield r = 0.708 and the regression equation y = 55.8 + 2.79x. Also, mean y = 71.125. What is the best predicted value of y for x = 5.7?
You have a random sample of size n, X1,X2,...Xn. Using the result in part (b) above, find the variance of the sample mean of that sample.
In past elections, the representative received 40 percent of the popular vote in that area of the state. She doubts whether it has changed much. How many registered voters should be sampled?
For example, color TV's are replaced at an average age of 8 years after purchase and a standard deviation of 1.5 years. What is the probability that someone will keep a color TV fewer than 10 years
The treatment is evaluated using a one tailed hypothesis test, and the test produces z = +1.85. Based on this result, what is the correct statistical decision?
Suppose a simple random sample of size 43 is selected from a population with = 11. Find the value of the standard error of the mean in each of the following cases (use the finite population correcti
A sample of 60 night-shift workers showed that the mean number of units produced was 351. At the .05 significance level, is the number of units produced on the night shift larger?
What size sample would be required to estimate the proportion of unemployed college students if we want the margin of error not to exceed 3 percent?
What is the best estimate of the average tread life in miles for the entire population of these tires?
Assuming this is literally true, how can it be explained? What facts and/or statistics would you need to know to expose this misleading claim?
A group of 50,000 random selected college student were surveyed about whether they have a TV in their dorm room. Only 75% said yes to the question. Which is a sample and which is a population.