Exam 7: Sampling Distributions and Sampling

TABLE 7-6 According to an article, 19% of the entire U.S. population have high-speed access to the Internet. Random samples of size 200 are selected from the U.S. population. -Referring to Table 7-6, the population mean of all the sample proportions is _____ .

The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 25 fish yields a mean of 3.6 pounds, what is the Z-score for this observation?

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The sampling distribution of the sample mean will be approximately normal only if the population sampled is normal.

TABLE 7-4 According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase. Random samples of size 50 are selected. -Referring to Table 7-4, what is the probability that a random sample of 50 will have at least 30% of customers who will make a purchase after visiting the web site?

As the size of the sample is increased, the standard deviation of the sampling distribution of the sample mean for a normally distributed population will stay the same.

TABLE 7-6 According to an article, 19% of the entire U.S. population have high-speed access to the Internet. Random samples of size 200 are selected from the U.S. population. -Referring to Table 7-6, among all the random samples of size 200, 90 % will have more than_______% who have high-speed access to the Internet.

The amount of pyridoxine (in grams) per multiple vitamin is normally distributed with µ = 110 grams and ?= 25 grams. A sample of 25 vitamins is to be selected. What is the probability that the sample mean will be between 100 and 120 grams?

Chunk sample is a type of probability sample.

Coverage error results in a(n)____ .

TABLE 7-6 According to an article, 19% of the entire U.S. population have high-speed access to the Internet. Random samples of size 200 are selected from the U.S. population. -Referring to Table 7-6, among all the random samples of size 200, _______ % will have between 14% and 24% who have high-speed access to the Internet.

If the expected value of a sample statistic is equal to the parameter it is estimating, then we call that sample statistic

Measurement error will become an ethical issue when the findings are presented without reference to sample size and margin of error.

The use of the finite population correction factor when sampling without replacement from finite populations will

To use the normal distribution to approximate the binomial distribution, we need ____and_____ to be at least 5.

An electronic appliance chain gathered customer opinions on their services using the customer feedback forms that are attached to the product registration forms. This is an example of a convenience sample.

A sample of 300 subscribers to a particular magazine is selected from a population frame of 9,000 subscribers. If, upon examining the data, it is determined that no subscriber had been selected in the sample more than once

Sampling error can be completely eliminated by taking larger sample sizes.

If the amount of gasoline purchased per car at a large service station has a population mean of $15 and a population standard deviation of $4 and a random sample of 4 cars is selected, there is approximately a 68.26% chance that the sample mean will be between $13 and $17.

For sample size 1, the sampling distribution of the mean will be normally distributed

If a simple random sample is chosen with replacement, each individual has the same chance of selection on every draw.