Answer: 0.701
Step-by-step explanation:
Formula : , where
significance level ,
Population standard deviation, n= sample size.
As per given, n= 22
Critical z- value for 90% confidence level :
Then,
Hence , error bound (EBM) of the confidence interval with a 90% confidence level= ± 0.701
Solution:
As we know reference angle is smallest angle between terminal side and X axis.
As cosine 45 ° is always positive in first and fourth quadrant.
i.e CosФ, Cos (-Ф) or Cos(2π - Ф) have same value.
As, Cos 45°, Cos (-45°) or Cos ( 360° - 45°)= Cos 315°are same.
So, Angles that share the same Cosine value as Cos 45° have same terminal sides will be in Quadrant IV having value Either Cos (-45°) or Cos (315°).
Also, Cos 45° = Sin 45° or Sin 135° i.e terminal side in first Quadrant or second Quadrant.
