Answer: c = 9
Step-by-step explanation:
12-9=3+9=12
 
        
             
        
        
        
Answer:
Step-by-step explanation:
Nick's age = x years
Lina's age =3*x = 3x
After 6 years,
Lina's age = 3x + 6
Nick's age = x + 6
3x + 6 = 2*(x+6)
3x + 6 = 2*x + 2*6
3x + 6 = 2x + 12      {Subtract 6 form both sides}
3x +6 - 6 = 2x + 12 - 6
3x  = 2x + 6    {subtract 2x from both sides}
3x - 2x = 2x + 6 - 2x
x = 6
Nick's age = 6 years
Lina's age =3*6 = 18 years
 
        
             
        
        
        
7.43: Let  denote the random variable for height and
 denote the random variable for height and  for the sample mean. Then if
 for the sample mean. Then if  is the mean of
 is the mean of 
So the probability that the difference between the sample and population means does not exceed 0.5 inch is

per the empirical or 68/95/99.7 rule.
7.44: For a sample of size <em>n</em>, the sample standard deviation would be  . We want to find <em>n</em> such that
. We want to find <em>n</em> such that

Comparing to the equation from the previous part, this means we would need

so a sample of at least 157 men would be sufficient.
 
        
             
        
        
        
Answer:
2 in
Step-by-step explanation: