12. Based on the pvalue for the test of Ho: \"female - Mmaie = 0 versus Ha: ermale - \"male 75 0, what decision do we make at .05 level of signicance, retain the null hypothesis or reject it? To investigate the effect of age on the duration of stay in the ICU, construct a scatterplot of duration of stay in the ICU versus age. Use Graph>Scatterplot to do this, choose option simple, and select ICU as Y variable, and age as X variable. Click OK. Does the scatterplot suggest that there is an association between variables ICU and age? Use Stat>Regression>Regression, use ICU as the response variable, and age as predictor. Use Minitab's output for regression analysis to answer questions below. 13. What percent of variation in response is explained using the predictor? R-sq= (Enter the number without % symbol into LON-CAPA). On the output, nd the table that lists predictors, coefficients, and their standard errors (right under the regression equation). Check Minitab's calculations of T and pvalue for the test if the slope of the population regression equation E(Y) = ,60 + x is zero. The hypotheses are H a : , = 0 vs H a : ,6] 9': 0. Output for the slope is in the second row of the table (for predictor age). Use Minitab's output to identify the sample slope bl = and its standard error 5.3.0,.) =