Answer:
Internal validity
Step-by-step explanation:
The internal validity here is weak
 Internal validity describes the extent to which an evidence weighs the cause and effect claim. In this study, the internal validity that brought about failure in the new exam is mainly due to the environment where the exam was written and not the new exam itself. 
So this validity is weak in claiming that the new exam is not a good substitute for the old exam.
Putting them in the same good environment might help the researchers to draw a better conclusion.
 
        
             
        
        
        
Answer:
Y = 32.7°
Step-by-step explanation:
We will apply the Cosine law in the given triangle XYZ,
x = 90 ft
y = 55 ft
z = 50 ft
We have to find the measure of angle Y.
y² = x² + z² - 2xzCosY
(55)² = (90)² + (50)² - 2(90)(50)cosY
3025 = 8100 + 2500 - 9000.cosY
9000.cosY = 10600 - 3025
cosY = 
         = 0.84167
Y = 
Y = 32.68 ≈ 32.7°
Therefore, measure of angle Y = 32.7° 
 
        
             
        
        
        
Answer:
$5,850
Step-by-step explanation:
4.5% = 0.045
0.045 x 130,000 = 5850
 
        
             
        
        
        
Answer: the answer is c 
Step-by-step explanation:
your welcome 
 
        
             
        
        
        
Answer:
 =
= +
+ +
 +
Step-by-step explanation:
 =multiple ways to climb a tower
=multiple ways to climb a tower
When n = 1, 
tower= 1 cm  
 = 1
= 1 
When n = 2, 
tower =2 cm   
  = 2
= 2 
When n = 3,
tower = 3 cm 
it can be build if we use three 1 cm blocks
 = 3
 = 3 
When n = 4, 
tower= 4 cm 
it can be build if we use four 1 cm blocks
 = 6
 = 6
When n > 5
tower height > 4 cm 
so we can use 1 cm, 2 cm and 4 cm blocks
so in that case if our last move is 1 cm block then  will be
 will be 
 n —1 cm
if our last move is 2 cm block then  will be
 will be 
 n —2 cm
 if our last move is 4 cm block then  will be
 will be 
 n —4 cm
 
 =
= +
+ +
 +