In Problems 5–12, find the indicated areas. For each problem, be sure to draw a standard normal curve and shade the area that is to be found.
Determine the total area under the standard normal curve
(a) to the left of z = -2.94 or to the right of z = 2.94
(b) to the left of z = -1.68 or to the right of z = 3.05
(c) to the left of z = -0.88 or to the right of z = 1.23
Step 1 of 5) To draw a standard normal curve and shade the area that is to be found. Determine the total area under the standard normal curve (a) to the left of z = -2.94 or to the right of z = 2.94 (b) to the left of z = -1.68 or to the right of z = 3.05 (c) to the left of z = -0.88 or to the right of z = 1.23. The contradictory results of the regression output occur because both x1 and x2 are related to the response variable y, as indicated by the correlation matrix. However, x1 and x2 are also related to each other. So, with x1 in the model, x2 adds little explanation. Likewise, with x2 in the model, x1 adds little explanation. The solution is to use only one explanatory variable. Which explanatory variable we choose is up to us. We can choose either the explanatory variable with the lower P-value or the explanatory variable that has the higher correlation with the response.
