B=10 and a=8 because if we look at that shape we can see that is two right angles on the both sides of that tape and it's suggesting that the shape is equally to there another shape of that right angle
        
             
        
        
        
Answer:
115.3 hertz
Step-by-step explanation:
For either interval, the value of the sample mean is given by the average of the lower and upper bound of the confidence interval. Since both intervals were constructed by using the same sample, both values should be equal.
For the first interval:

For the second interval:

 
        
             
        
        
        
 Answer:
 The three unknown angles X, Y , and Z are:
X = 40, Y = 20, and Z = 120
Step-by-step explanation:
Let's name X the measure of the first angle, Y the measure of the second one, and Z that of the third one. 
Then we can create the following equations:
X = 2 Y
Z = 100 + Y
and
X + Y + Z = 180
So we use the first equation and the second one to substitute for the variable X and Z in the thrid equation:
2 Y + Y + (100 + Y) = 180
4 Y + 100 = 180
4 Y = 80
Y = 80/4 = 20
Then X = 40, Y = 20, and Z = 120
 
        
             
        
        
        
Answer:
im pretty sure its a
Step-by-step explanation: