Answer:
Step-by-step explanation:
P-6 is an expression, your question is incomplete.
Answer: 320 boys
Step-by-step explanation: you would first take the total number (720) and divide it by the total number shown in the ratio (5+4=9)
720/9= 80
You would then take 80 and multiply it by 4 because that is the number representing the boys
80*4= 320
Answer: 756
Step-by-step explanation:
Given : The proportion of adults over 50 never graduated from high school. = 0.23
Margin of error : E=0.03
Significance level : 
Critical value : 
The formula to find the sample size is given by:_

i.e. 
Hence, the required minimum sample size = 756
Answer:
x = 7 degrees
Step-by-step explanation:
4x-5 = 2x + 9
-2x -2x
2x-5 = 9
+5 +5
2x = 14
2x/2 =14 /2
x= 7