Use the Normal Distribution table to find the proportion of
Use the Normal Distribution table to find the proportion of the normal curve that is At or below a z-score of -1.50 At or above a z-score of -1.75 Between the z-scores of -1.50 and .50 Between the z-scores of 1.00 and .25 Between the z-scores of 1.25 and .50
Solution
At or below a z-score of -1.50
Using a table/technology, the left tailed area of this is          
           
 P(z <   -1.5   ) =    0.0668 [ANSWER]
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 At or above a z-score of -1.75
Using a table/technology, the right tailed area of this is          
           
 P(z >   -1.75   ) =    0.9599 [ANSWER]
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Between the z-scores of -1.50 and .50
z1 = lower z score =    -1.5      
 z2 = upper z score =     0.5      
           
 Using table/technology, the left tailed areas between these z scores is          
           
 P(z < z1) =    0.0668      
 P(z < z2) =    0.6915
           
 Thus, the area between them, by subtracting these areas, is          
           
 P(z1 < z < z2) =    0.6247 [ANSWER]
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Between the z-scores of 1.00 and .25
z1 = lower z score =    0.25      
 z2 = upper z score =     1      
           
 Using table/technology, the left tailed areas between these z scores is          
           
 P(z < z1) =    0.5987      
 P(z < z2) =    0.8413      
           
 Thus, the area between them, by subtracting these areas, is          
           
 P(z1 < z < z2) =    0.2426 [ANSWER]
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Between the z-scores of 1.25 and .50
z1 = lower z score =    0.5      
 z2 = upper z score =     1.25      
           
 Using table/technology, the left tailed areas between these z scores is          
           
 P(z < z1) =    0.6915      
 P(z < z2) =    0.8944
           
 Thus, the area between them, by subtracting these areas, is          
           
 P(z1 < z < z2) =    0.2029 [ANSWER]


