1.A regression equation Y = a + bX is used to forecast the value of Y for a given value of X.
Which TWO of the following increase the reliability of the forecast?
A.A correlation coefficient numerically close to 1
B. Working to a higher number of decimal places of accuracy
C.Forecasting for values of X outside the range of those used in the sample
D.A large sample is used to calculate the regression equation
2.Using data from twelve European countries, it has been calculated that the correlation between the level of car ownership and the number of road deaths is 0.73.
Which TWO of the statements shown follow from this?
A.High levels of car ownership cause high levels of road deaths
B.There is a strong relationship between the level of car ownership and the number of road deaths
C.53% of the variation in the level of road deaths from one country to the next can be explained by the corresponding variation in the level of car ownership
D.73% of the variation in the level of road deaths from one country to the next can be explained by the corresponding variation in the level of car ownership
点击加载更多评论>>