Exam 14: Tests of Hypotheses Based on Count Data

arrow
  • Select Tags
search iconSearch Question
  • Select Tags

When conducting a chi-square test for a goodness-of-fit, the number of degrees of freedom is given by __________.

(Short Answer)
4.9/5
(39)

A small computed X2X^{2} value for a contingency table reveals which of the following concerning the two variables?

(Multiple Choice)
4.9/5
(36)

The null hypothesis in a chi-square test of independence is that there is no relationship between the two variables.

(True/False)
4.8/5
(32)

If the observed frequencies are exactly equal to the expected frequencies in a chi-square test, the value of X2X^{2} is

(Multiple Choice)
4.7/5
(44)

For a contingency table, the expected frequency values are based on the assumption that the null hypothesis is true.

(True/False)
4.9/5
(43)

If n=400n=400 , an hypothesis test may be conducted to test a population proportion using the normal curve if pp is between __________ and __________.

(Short Answer)
4.8/5
(33)

It is claimed that at most 70%70 \% of all local businesses last more than one year. The null hypothesis p=0.70p=0.70 is tested against the alternative p>0.70p>0.70 at α=0.05\alpha=0.05 for a sample size of n=11n=11 . Suppose eight of the businesses lasted more than one year. Which of the following decisions should be made regarding the null hypothesis?

(Multiple Choice)
4.8/5
(35)

An office worker claims that at most 30%30 \% of the phone calls he makes are the nonbusiness type. Conduct a two-tailed test of p=0.30p=0.30 at α=0.05\alpha=0.05 , if a random sample of 13 of his calls reveals 8 nonbusiness calls.

(Essay)
4.7/5
(33)

A cereal company is marketing a new breakfast food. In a random sample of 250 people who have tried the product, 175 said that they would buy it again. What can we state with 99%99 \% confidence about the maximum size of our error if we use the sample proportion 175250=0.70\frac{175}{250}=0.70 as an estimate of the actual population proportion of people who will buy the product a second time?

(Short Answer)
4.7/5
(34)

For a particular error value and confidence level, the maximum value that the sample size formula can assume occurs when pp equals __________.

(Short Answer)
4.7/5
(31)

In determining the necessary sample size for 95%95 \% confidence interval, the value 0.95 must be substituted into the formula for zα/2z_{\alpha / 2} .

(True/False)
4.8/5
(36)

A sample of 210 people were telephoned. The number of rings that have fully elapsed before each person answered the phone are recorded below.  A sample of 210 people were telephoned. The number of rings that have fully elapsed before each person answered the phone are recorded below.    -At the 0.05 level of significance, does it appear that the data may be looked upon as a random sample from a binomial population with  p=0.4  and  n=6  ? Conduct the goodness-of-fit test. -At the 0.05 level of significance, does it appear that the data may be looked upon as a random sample from a binomial population with p=0.4p=0.4 and n=6n=6 ? Conduct the goodness-of-fit test.

(Essay)
4.8/5
(30)

In a study to determine if a college student's year in college is independent of his or her major, a sample of 200 students was found to contain 40 juniors and 50 accounting majors. Then, the expected frequency of junior accounting majors is

(Multiple Choice)
4.8/5
(42)

A drug company wants to know whether the probability is really 0.20 that one of their products will produce side effects. In a random sample of 150 consumers of the product, 42 were victims of side effects. Conduct a one-tailed test where the alternative is that the probability is greater than 0.20 . Use α=0.01\alpha=0.01 .

(Essay)
4.9/5
(34)

In order to use the maximum error of estimate formula involving the sample value x/n,nx / n, n must be large enough to justify the normal curve approximation to the binomial distribution.

(True/False)
4.7/5
(30)

The X2X^{2} statistic should never be applied to contingency tables if some of the expected frequencies are less than 5.

(True/False)
5.0/5
(36)

A university placement office wants to estimate the percentage of graduates that obtain jobs within one month of graduation. They want to be 98%98 \% confident in their result and be within 5%5 \% of the true percentage. Find the necessary sample size for this experiment, and find a 98%98 \% confidence interval if 30%30 \% of the sample received jobs within one month of graduation.

(Essay)
4.8/5
(34)

The chi-square statistic for a 7×47 \times 4 contingency table will have __________ degrees of freedom.

(Short Answer)
4.9/5
(44)

The value of α\alpha has a definite effect on the number of degrees of freedom used to determine X2\mathrm{X}^{2} .

(True/False)
4.9/5
(42)

A company is marketing a laser disk recorder. A survey of 80 randomly selected male students at a college reveals that 45 would be interested in buying such a recorder. A corresponding survey of 120 female students reveals that 75 want to buy it. Test the hypothesis that there is no difference between the males and the females on this issue. Use the 5%5 \% significance level.

(Essay)
4.8/5
(30)
Showing 21 - 40 of 43
close modal

Filters

  • Essay(0)
  • Multiple Choice(0)
  • Short Answer(0)
  • True False(0)
  • Matching(0)