护士小李在为男病人导尿时，将阴茎抬起，使阴茎与腹壁成600，他这样操作的目的是
A使耻骨下弯消失
B使耻骨后弯消失
C顺利通过尿道的3个狭窄处
D使耻骨上弯消失
E.E．使耻骨前弯消失
查看答案
When estimating a demand function for a good where quantity demanded is a linear function of the price, you should
A. not include an intercept because the price of the good is never zero.
B. use a one-sided alternative hypothesis to check the influence of price on quantity.
C. use a two-sided alternative hypothesis to check the influence of price on quantity.
D. reject the idea that price determines demand unless the coefficient is at least 1.96.
The t-statistic is calculated by dividing
A. the OLS estimator by its standard error.
B. the slope by the standard deviation of the explanatory variable.
C. the estimator minus its hypothesized value by the standard error of the estimator.
D. the slope by 1.96.
If the absolute value of your calculated t-statistic exceeds the critical value from the standard normal distribution, you can
A. reject the null hypothesis.
B. safely assume that your regression results are significant.
C. reject the assumption that the error terms are homoskedastic.
D. conclude that most of the actual values are very close to the regression line.
Under the least squares assumptions (zero conditional mean for the error term, Xi and Yi being i.i.d., and Xi and ui having finite fourth moments), the OLS estimator for the slope and intercept
A. has an exact normal distribution for n > 15.
B. is BLUE.
C. has a normal distribution even in small samples.
D. is unbiased.
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