Answer:
The correct statement is
The null hypothesis is 
The alternative hypothesis is 
Step-by-step explanation:
From the question we are told that
The population proportion is p = 0.18
The sample size is n = 1240 airplane
The number of airplane is k = 310
Generally the sample proportion is

=> 
=> 
The null hypothesis is 
The alternative hypothesis is 
Answer:
x=70
Step-by-step explanation:
the angles opposite 3.5 equal 55 degrees
180-55-55=70