Math534 - Study guides, Class notes & Summaries

1. Question: Suppose a random sample of 400 is selected from a population with a standard deviation of 5. If the sample mean is 25, the 98% confidence interval to estimate the population mean is between ________. 2. Question: The point estimate of the population mean is _________. 3. Question: Suppose a random sample of 50 is drawn from a population whose standard deviation is unknown. If the sample mean is 70 and the sample standard deviation is 5, the 92% confidence interval to estimate the ...

of a statistic (mean, proportion, or standard deviation, etc.). There is always a risk ofsampling error associated with an estimate. Confidence intervals are useful forestablishing bounds for estimating, in particular, the mean or standard deviation, butalso regression coefficients, proportions, frequency rates, and differences betweenpopulations. Also, a 95% confidence interval indicates that for 19 out of 20 samplestakenfromthesamepopulation,theseintervalswillcontaintheparameterstudied,withama...

1. Question: A value of -1 for the coefficient of correlation between two variables means that the two variables are _____________. 2. Question: If there is positive correlation between two sets of numbers, then ____________-. 3. Question: If the correlation coefficient between variables X and Y is roughly zero, then ___________. 4. Question: Determine the Pearson product-moment correlation coefficient for the following data. 5. Question: A quality manager is developing a regression model to...

1. Question: Scores on a certain exam are normally distributed with a mean of 90 and a variance of 25. What is the z-value for a score of 80? 2. Question: Scores on a certain exam are normally distributed with a mean of 90 and a variance of 25. What is the probability of obtaining a score less than 80? 3. Question: Which one of the following is not a characteristic of a normal distribution? 4. Question: If the z-value of a given x value is positive, it means that ___________. 5. Question: As...

1. Question:Arealestateanalysthasdevelopedamultipleregressionline,y=60+0.068x1–2.5x2,topredicty=themarketpriceofahome(in $1,000s),usingindependentvariables,x1=thetotalnumberofsquare feetoflivingspace,andx2=theageofthehouseinyears.The regressioncoefficientofx2suggeststhis: _____. 2. Question:Thefollowingisapartialcomputeroutputofamultipleregressionanalysis of a data set containing 20 sets of observations on thedependentvariable. Theregressionequationis SALEPRIC=1470+0.8145LANDVAL+0.8204IMP...

1. Question: In a hypothesis test, the test statistic computed from the sample data is considered extreme or significant if it is __________ 2. Question: A test of the hypotheses, H0: p = 0.18 and H1: p ≠ 0.18 is a _______________. 3. Question: An analyst tested the null hypothesis µ ≥ 30 against the alternative hypothesis that µ < 30. The analyst reported a p-value of 0.07. For what significance level of α will the null hypothesis would be rejected? 4. Question: The dean of a busi...

Predictiveanalyticsisaninnovativeanalyticsdivisionthatuseshistoricaldatacombinedwith mathematical simulation, data mining techniques and machine learning to makeforecasts about future results.In order to detect threats and prospects, businessesemploy predictiveanalytics tofindtrendsin thisknowledge. Regression analysis refers to a process of mathematically sorting out which factorscouldhaveaneffect.Forasmallenterprise,thevalueofregressionanalysis isthatithelps decide which variables matter most...

1. Question: A value of -1 for the coefficient of correlation between two variables means that the two variables are _____________. 2. Question: If there is positive correlation between two sets of numbers, then ____________-. 3. Question: If the correlation coefficient between variables X and Y is roughly zero, then ___________. 4. Question: Determine the Pearson product-moment correlation coefficient for the following data. 5. Question: A quality manager is developing a regression model to...