Answer:

Step by step
Remember, a reference angle is a positive acute angle that represents an angle θ of any measurement.
a)
, then its reference angle is 
b)
is in the second cuadrant, then its reference angle is 
c)
, then it is in the first cuadrant and the reference angle is
.
d)
and it is in the third cuadrant, then its reference angle is 
Answer:
Step-by-step explanation:
Weight decreased = 108 - 88 = 20 Kg
Percentage decrease = 
= 18.52%
Answer:
The value is 8500
Step-by-step explanation:
Of means multiply and is means equals
6% * V = 510
Change percent to decimal form
.06V = 510
Divide each side by .06
V = 510/.06
V =8500
Answer: 1.509
Step-by-step explanation:
The formula of Margin of Error for (n<30):-

Given : Sample size : n= 22
Level of confidence = 0.99
Significance level : 
Using the t-distribution table ,
Critical value : 
Standard deviation: 
Then, we have

Hence, the margin of error for a 99% confidence interval for the population mean =1.509