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MATH STATISTIC 302 - Seffy

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Question;A fiA field researcher is;gathering data on the trunk diameters of mature pine and spruce trees in a;certain area. The following are the results of his random;sampling. Can he conclude, at the.10 level of significance, that the;average trunk diameter of a pine tree is greater than the average diameter;of a spruce tree?;Pine;trees;Spruce;trees;Sample size;40;70;Mean trunk diameter (cm);45;39;Sample variance;100;150;A.;The data support the claim because the test value 2.78 is greater than;1.64.;B.;The data do not support the claim because the test value 1.29 is greater;than 1.28.;C.The;data do not support the claim because the test value 1.29 is less than;1.64.;D.The;data support the claim because the test value 2.78 is greater than 1.28.;Reset Selection;Question 2 of 17;1.0 Points;MeMembers of the general adult;population volunteer an average of 4.2 hours per week. A random sample;of 20 female college students and 18 male college students produced the;results given in the table below. At the.01 level of significance, is;there sufficient evidence to conclude that a difference exists between the;mean number of volunteer hours per week for male and female college;students?;Females;Males;Sample size;20;18;Sample mean;3.8;2.5;Sample variance;3.5;2.2;A.No;because the test value 2.38 is greater than the critical value;B.No;because the test value 2.38 does not exceed the critical value;C.No;because the test value 2.90 is greater than the critical value;D.Yes;because the test value 2.90 is greater than the critical value;Reset Selection;Question 3 of 17;1.0 Points;SoSome defendants in criminal proceedings plead;guilty and are sentenced without a trial, whereas others who plead innocent;are subsequently found guilty and then are sentenced. In recent years;legal scholars have speculated as to whether sentences of those who plead;guilty differ in severity from sentences for those who plead innocent and;are subsequently judged guilty. Consider the data given below on;defendants accused of robbery, all of whom, by the way, had previous prison;records. At the.01 level of significance, do these data suggest that;the proportion of all defendants in these circumstances who plead guilty;and are sent to prison differs from the proportion who are sent to prison;after pleading innocent and being found guilty?;Plea;Guilty;Not Guilty;Number;judged guilty;n1 = 191;n2 = 64;Number;sentenced to prison;x1 = 101;x2 = 56;Sample;proportion;.529;.875;A.No;because the test value -4.94 is outside the interval (-1.96, 1.96);B.No;because the test value -1.96 is inside the interval (-2.58, 2.58);C.Yes;because the test value 2.58 is inside the interval (-4.94, 4.94);D.Yes;because the test value -4.94 is outside the interval (-2.58, 2.58);Reset Selection;Part 2;of 8 -;Question 4 of 17;1.0 Points;Outliers;are observations that;A.render;the study useless;B.lie;outside the sample;C.disrupt;the entire linear trend;D.lie;outside the typical pattern of points;Reset Selection;Question 5 of 17;1.0 Points;The;marketing manager of a large supermarket chain would like to use shelf;space to predict the sales of pet food. For a random sample of 12;similar stores, she gathered the following information regarding the shelf;space, in feet, devoted to pet food and the weekly sales in hundreds of;dollars..;Store;1;2;3;4;5;6;Shelf;Space;5;5;5;10;10;10;Weekly;Sales;1.6;2.2;1.4;1.9;2.4;2.6;Store;7;8;9;10;11;12;Shelf;Space;15;15;15;20;20;20;Weekly;Sales;2.3;2.7;2.8;2.6;2.9;3.1;Compute the value of the sample correlation coefficient between weekly;sales and shelf space.;A.0.827;B.0.684;C.0.308;D.0.652;Reset Selection;Question 6 of 17;1.0 Points;In a;simple linear regression analysis, the following sum of squares are;produced: =;400= 80=;320;The;proportion of the variation inYthat is explained by the;variation inXis;A.20%;B.50%;C.25%;D.80%;Reset Selection;Question 7 of 17;1.0 Points;A;correlation value of zero indicates.;A.a;weak linear relationship;B.no;linear relationship;C.a;strong linear relationship;D.a;perfect linear relationship;Reset Selection;Question 8 of 17;1.0 Points;The;standard error of the estimate, sest, is essentially the;A.standard;deviation of the residuals;B.mean;of the explanatory variable;C.standard;deviation of the explanatory variable;D.mean;of the residuals;Reset Selection;Part 3;of 8 -;Question 9 of 17;2.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;A survey of employees at a company finds that 32 of the 88 employees who;drive to work were ever late during the past year, and 18 of the 64;employees who took public transportation were ever late during the past;year. At? = 0.10, is there a;difference between the proportion of employees who drove who were ever late;and the proportion of employees who took public transportation who were;ever late?;Find the test value for the difference in the proportion of employees who;were ever late for work in the past year.;Answer: Round;your answer to two decimal places.;What is your decision for this test?;1. The test value is greater than the critical value of 1.960.;2. The test value is less than the critical value of 1.645.;3. The test value is greater than the critical value of 1.282.;4. The test value is less than the critical value of 1.960.;Answer;Enter only a 1, 2, 3 or 4 for your answer.;Part 4;of 8 -;Question 10 of 17;1.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;A company has observed that there is a linear relationship between indirect;labor expense (ILE), in dollars, and direct labor hours (DLH). Data for;direct labor hours and indirect labor expense for 18 months are given in;the file ILE_and_DLH.xlsx;Treating;ILE as the response variable, use regression to fit a straight line to all;18 data points.;Using your estimated regression output, predict the indirect labor expenses;for a month in which the company has 31 direct labor hours.;Place your answer, rounded to 1 decimal place, in the blank. Do;not use any stray punctuation marks or a dollar sign. For;example, 458.9 would be a legitimate entry.;Question 11 of 17;1.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;The marketing manager of a large supermarket chain;would like to determine the effect of shelf space (in feet) on the weekly;sales of international food (in hundreds of dollars). A random sample of 12;equal ?sized stores is selected, with the following results;Store;Shelf;Space(X);Weekly;Sales(Y);1;10;2.0;2;10;2.6;3;10;1.8;4;15;2.3;5;15;2.8;6;15;3.0;7;20;2.7;8;20;3.1;9;20;3.2;10;25;3.0;11;25;3.3;12;25;3.5;Find the equation of the regression line for these data. What is the;value of the standard error of the estimate? Place your answer;rounded to 3 decimal places, in the blank. Do not use a dollar;sign. For example, 0.345 would be a legitimate entry.;Part 5;of 8 -;Question 12 of 17;1.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;Are America's top chief executive officers (CEOs) really worth all that money?;One way to answer this question is to look at the annual company percentage;increase in revenue versus the CEO's annual percentage salary increase in;that same company. Suppose that a random sample of companies yielded the;following data;percent;change for corporation;15;12;3;12;28;6;8;2;percent;change for CEO;6;17;-4;12;32;-1;7;2;Do these data indicate that the population mean percentage increase in;corporate revenue is greater than the population mean percentage increase;in CEO salary? Use a 5% level of significance. What is the;p-value associated with this test of hypothesis? Place your;answer, rounded to 3 decimal places, in the blank. For example, 0.134;would be a legitimate entry.;Question 13 of 17;1.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;Q-Mart is interested in comparing its male and female customers. Q-Mart would;like to know if the amount of money spent by its female charge customers;differs, on average, from the amount spent by its male charge;customers. To answer this question, an analyst collected random samples of;25 female customers and 22 male customers.;Based on these samples, on average, the 25 women charge customers spent;$102.23 and the 22 men charge customers spent $86.46. Moreover, the sample;standard deviation of the amount charged by the 25 women was $93.393, and;the sample standard deviation of the amount charged by the 22 men was;$59.695.;Suppose, using a 10% level of significance, you wish to know if there;is sufficient evidence for Q-Mart to conclude that, on average, the amount;spent by women charge customers differs from the amount spent by men charge;customers. That is suppose you wish to test;H0;versus H1;Assuming that the amounts spent by male and female charge customers at;Q-Mart are normally distributed, based on the procedure advocated by;Bluman, what is the test value that you would use to conduct this test of;hypothesis? Place your answer, rounded to 3 decimal places, in the blank.;For example, 0.123 would be a legitimate entry.;Part 6;of 8 -;Question 14 of 17;3.0 Points;Accepted;characters;numbers, decimal point markers (period or comma), sign indicators (-);spaces (e.g., as thousands separator, 5 000), "E" or;"e" (used in scientific notation). NOTE: For;scientific notation, a period MUST be used as the decimal point marker.;Complex numbers should be in the form (a + bi) where "a" and;"b" need to have explicitly stated values.;For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas;{9i} is not.;Researchers conducted an experiment to measure the effect of a drug on;improving the quality of sleep as determined by how many more minutes of;REM sleep were measured for each participant. One group of participants;were given the experimental drug, the other (control) group was given a;placebo. Does the evidence indicate that the drug improved the amount of;REM sleep at a 0.01 level of significance? Answer each of the following;parts.;Experimental;group;Control;group;sample;size;35;50;mean;sleep improvement;12.8;9.1;sample;variance;56.3;61.2;What is the test value for this hypothesis test?;Answer;Round your answer to two decimal places.;What is;the P-value for this hypothesis test?;Answer;Round your answer to three decimal places.;What is the conclusion of this hypothesis test? Choose one.;1. There is sufficient evidence to show that the experimental drug;improved the quality of sleep.;2. There is not sufficient evidence to show that the experimental;drug improved the quality of sleep.;3. There is sufficient evidence to show that the quality of sleep is;different for the experimental drug than for the control drug.;4. There is not sufficient evidence to show that the control drug;decreased the quality of sleep.;Answer;Enter only a 1, 2, 3 or 4 for your answer.;Part 7;of 8 -;Question 15 of 17;1.0 Points;When;testing the equality of two population variances, the test statistic is the;ratio of the population variances, namely.;True;False;Reset Selection;Part 8;of 8 -;Question 16 of 17;1.0 Points;In a;simple linear regression problem, the least squares line is y' = -3.2 +;1.3X, and the coefficient of determination is 0.7225. The coefficient of;correlation must be ?0.85.;True;False;Reset Selection;Question 17 of 17;1.0 Points;In a;simple linear regression problem, if the coefficient of determination is;0.95, this means that 95% of the variation in the explanatory variable X;can be explained by regression.;True;False;Reset Selection

 

Paper#61743 | Written in 18-Jul-2015

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