Answer:
atleast 385
Step-by-step explanation:
Given that an electrical power company is looking to expand into a new market. Before they commit to supplying the new area with electricity, they would like know the mean daily power usage for homes there. 
Population std deviation = 
Sample size =
STd error of sample mean = 
Margin of error for 95% would be Critical value ( std error)
Here since population std dev is known we can use Z critical value= 1.96

Sample size should be atleast 385
 
        
             
        
        
        
Answer:
46 
Step-by-step explanation:
Solution :
Remember that the sum of complementary angles is always 90°.
First, finding the value of x :
Set up an equation :
 ( Being complementary angles )
Solve for x
 { Remove unnecessary parentheses }
 { Combine like terms }
 { Subtract 3 from 30 }
 { Move 27 to right hand side and change it's sign }
 { Subtract 27 from 90}
 { Divide both sides by 9 }
The value of X is 7°
Now, Replacing the value of x in order to find the value of  B
 { Plug the value of x }
 { Multiply 7 by 7 }
 { Subtract 3 from 49 }
The measure of  B is 46°
 
        
             
        
        
        
The top half is called the numerator. 
The bottom is called the denominator.