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QNT 275 Week 5 Practice Connect Knowledge Check

A sequence of values of some variable or composite of variables taken at successive, uninterrupted time periods is called a

seasonal factor.

cyclical component.

moving average.

least squares (linear) trend line.

time series.

The chi-square goodness-of-fit is _________ a one-tailed test with the rejection region in the right tail.

never

sometimes

always

When the moving average method is used to estimate the seasonal factors with quarterly sales data, a ______ period moving average is used.

4

8

5

2

3

An experiment consists of 400 observations and four mutually exclusive groups. If the probability of a randomly selected item being classified into any of the four groups is equal, then the expected number of items that will be classified into group 1 is _____.

100

125

150

25

The range for r2 is between 0 and 1, and the range for r is between ____________.

There is no limit for r.

−1 and 0

0 and 1

−1 and 1

In simple regression analysis, the quantity that gives the amount by which Y (dependent variable) changes for a unit change in X (independent variable) is called the

correlation coefficient.

coefficient of determination.

slope of the regression line.

standard error.

y-intercept of the regression line.

The chi-square goodness-of-fit test will be valid if the average of the expected cell frequencies is ______________.

between 0 and 5

less than 5

at least 5

greater than 0

at least 1

Suppose that the unadjusted seasonal factor for the month of April is 1.10. The sum of the 12 months’ unadjusted seasonal factor values is 12.18. The normalized (adjusted) seasonal factor value for April

cannot be determined with the information provided.

is equal to 1.1.

is larger than 1.1.

is smaller than 1.1.

One use of the chi-square goodness-of-fit test is to determine if specified multinomial probabilities in the null hypothesis are correct.

True

False

The slope of the simple linear regression equation represents the average change in the value of the dependent variable per unit change in the independent variable (X).

True

False

The upward or downward movement that characterizes a time series over a period of time is referred to as _____________.

irregular variation

seasonal variation

a trend

cyclical variation

A major drawback of the aggregate price index is that

it is difficult to compute.

percentage comparisons cannot be made to the base year.

it does not take into account the fact that some items in the market basket are purchased more frequently than others.

it is computed by using the values from a single time series or based on a single product.

The correlation coefficient may assume any value between

0 and 1.

0 and 8.

−1 and 1.

−1 and 0.

−∞ and ∞.

The number of degrees of freedom associated with a chi-square test for independence based upon a contingency table with 4 rows and 3 columns is _____.

5

7

12

6

In simple linear regression analysis, we assume that the variance of the independent variable (X) is equal to the variance of the dependent variable (Y).

True

False

hose fluctuations that are associated with climate, holidays, and related activities are referred to as __________ variations.

trend

cyclical

seasonal

irregular

A ______________________ measures the strength of the relationship between a dependent variable (Y) and an independent variable (X).

coefficient of determination

standard error

slope

correlation coefficient

When we carry out a chi-square test of independence, the chi-square statistic is based on (r × c) − 1 degrees of freedom, where r and c denote, respectively, the number of rows and columns in the contingency table.

True

False

The correlation coefficient is the ratio of explained variation to total variation.

True

False

A multinomial probability distribution describes data that are classified into two or more categories when a multinomial experiment is carried out.

True

False

The ____________________ is the proportion of the total variation in the dependent variable explained by the regression model.

correlation coefficient

slope

coefficient of determination

standard error

The strength of the relationship between two quantitative variables can be measured by

both the coefficient of correlation and the coefficient of determination.

the coefficient of determination.

the slope of a simple linear regression equation.

the y-intercept of the simple linear regression equation.

the coefficient of correlation.