BUSI 230 HW 9.5, HW 11.4, HW 12.1, HW 12.2 Connect Exercises Week 7 solutions complete answers

BUSI 230 HW 9.5, HW 11.4, HW 12.1, HW 12.2 Connect Exercises Week 7 solutions complete answers 

 

BUSI 230 HW 9.5 Hypothesis Tests for a Standard Deviation Assignment 

 

A random sample of size 16 from a normal distribution has standard deviation =83. Test H=66 versus . Use the =0.01 level of significance.

The hypotheses are provided above.

Find the critical value.

Compute the test statistic. Round the answer to three decimal places as needed.

Determine whether to reject .

State a conclusion.

 

Babies: A sample of 25 one-year-old girls had a mean weight of 24.1 pounds with a standard deviation of 4.3 pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is less than 7 pounds. Do the data provide convincing evidence that the pediatrician's claim is true? Use the =0.05 level of significance.

State the appropriate null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to three decimal places.

Compute the test statistic. Round the answer to three decimal places.

Determine whether to reject .

State a conclusion.

 

Watching TV: The  general Social Survey asked a large number of people how much time they spent watching TV each day. The mean number of hours was 3.09 with a standard deviation of 2.75. Assume that in a sample of 36 teenagers, the sample standard deviation of daily TV time is 3.4 hours, and that the population of TV watching times is normally distributed. Can you conclude that the population standard deviation of TV watching times for teenagers is greater than 2.75? Use the =0.01 level of significance.

State the appropriate null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to three decimal places.

Compute the test statistic. Round the answer to three decimal places.

Determine whether to reject .

State a conclusion.

 

IQ scores: Scores on an IQ test are normally distributed. A sample of 25 IQ scores had standard deviation =8. The developer of the test claims that the population standard deviation is less than =9. Do these data provide sufficient evidence to support this claim? Use the =0.05 level of significance.

State the appropriate null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to three decimal places.

Compute the test statistic. Round the answer to three decimal places.

Determine whether to reject .

State a conclusion.

 

Liberty University BUSI 230 HW 11.4 Hypothesis Tests for Two Population Standard Deviations Assignment complete solutions answers and more!

 

Find the critical value f0.10 for F3,10. Round your answer to two decimal places.

 

An -test with  degrees of freedom in the numerator and  degrees of freedom in the denominator produced a test statistic whose value was . The null and alternate hypotheses were H0:=  versus H1 < .

Find the critical values f0.10 and f0.01 for f8,10.

Do you reject  at the  and the  level?

 

Sugar content: A broth used to manufacture a pharmeceutical product has its sugar content, in milligrams per milliliter, measured several times on each of three successive days. Can you conclude that the variability of the process is lesser on the second day than on the third day? Let  denote the variability of sugar content on the first day and  denote the variability of sugar content on the third day. Use the =0.01 level and the critical value method with the table.

State the appropriate null and alternate hypotheses.

Find the critical value. Round the answer to two decimal places.

Compute the test statistic. Round the answer to two decimal places.

Determine whether to reject .

State a conclusion.

 

Can you conclude that the standard deviation of the breaking strength Composite 2 is greater? Use the =0.05 level of significance.

State the null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to two decimal places.

Compute the test statistic. Round the answer to two decimal places.

Determine whether to reject .

State a conclusion.

 

Frozen computer: A computer system administrator noticed that computers running a particular operating system seem to freeze up more often as the installation of the operating system ages. She measures the time (in minutes) before freeze-up for 6 computers one month after installation and for 6 computers seven months after installation. The results are shown. Can you conclude that the time to freeze-up differs in variability in the seventh month and the first month after installation?  Let  denote the variability in time to freeze-up in the first month after installation. Use the =0.05 level and the critical value method with the table.

State the null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to two decimal places.

Compute the test statistic. Round the answer to two decimal places.

Determine whether to reject .

State a conclusion.

 

Are you smarter than your older brother? In a study of birth order and intelligence, IQ tests were given to - and -year-old men to estimate the size of the difference, if any, between the mean IQs of firstborn sons and secondborn sons. The following data for  firstborn sons and  secondborn sons are consistent with the means and standard deviations reported in the article. Assume that the samples come from normal populations.

Can you conclude that the standard deviation of IQ differs between firstborn and secondborn sons? Let  denote the standard deviation in the IQs of firstborn sons. Use the =0.05 level.

State the null and alternate hypotheses.

This hypothesis test is a

Find the critical value. Round the answer to at least two decimal places.

Compute the test statistic. Round the answer to at least two decimal places.

Determine whether to reject .

State a conclusion.

 

Liberty University BUSI 230 HW 12.1 Testing Goodness of Fit Assignment complete solutions answers and more!

 

Can you conclude that the distribution of observed frequencies differs from that given by the expected frequencies? Use Excel and the -value method; use the =0.005 level of significance.

(a)Find the -value. Use Excel; round to four decimal places.

(b)Write a conclusion.

 

Following are observed frequencies. The null hypothesis is

H0: P1=0.20, P2=0.10, P3=0.10, P4=0.6

Can you conclude that the distribution of observed frequencies differs from that given by the null hypothesis? Use the =0.01 level of significance.

(a)Compute the expected frequencies.

(b)Find the -value. Use Excel; round to four decimal places.

 

Grade distribution: A statistics teacher claims that, on the average, 10.00 of her students get a grade of A, 15.00 get a B, 20.00 get a C, 30.00 get a D, and 25.00 get an F. The grades of a random sample of 100 students were recorded. The following table presents the results.

Can you conclude that the distribution of the grades differs from the teacher’s claim? Use the =0.05 level of significance.

(a)How many students got a D? How many got a C?

(b)Which grades were given more often and less often than expected?

(c)Write a conclusion.

 

False alarm: The numbers of false fire alarms were counted each month at a number of sites. The results are given in the following table.

Can you conclude that false alarms are not equally likely to occur in any month? Use the =0.01 level of significance.

(a) Find the -value. Use Excel; round to four decimal places.

(b) Write a conclusion.

 

Liberty University BUSI 230 HW 12.2 Test for Independence Assignment complete solutions answers and more!

 

A recent study examined the effects of carbon monoxide exposure on a group of construction workers. The following table presents the numbers of workers who reported various symptoms, along with the shift (morning,  evening,  or night) that they worked.

Test the hypothesis of independence. Use the =0.05 level of significance and the P-value method with the TI-84 Plus calculator. What do you conclude?

State the null and alternate hypotheses.

Determine whether to reject .

State a conclusion.

 

No smoking: The General Social Survey conducted a poll of  adults in which the subjects were asked whether they agree that the government should prohibit smoking in public places. In addition, each was asked how many people lived in his or her household. The results are summarized in the following contingency table.

Test the hypothesis of independence. Use the 0.05 level of significance and the P-value method with the TI-84 Plus calculator. What do you conclude?

(a) State the null and alternate hypotheses.

(b) Find the P-value. Round your answer to at least four decimal places.

(c) Determine whether to reject .

(d) State a conclusion.

 

How big is your family? A survey asked a sample of  adults how many children they had, and also how many siblings (brothers and sisters) they had. The results are summarized in the following contingency table.

(a)Compute the expected frequencies under the null hypothesis. Round your answers to two decimal places.

(b)Can you conclude the number of siblings, and number of children, are not independent? Use Excel and the =0.01 level of significance.