Answer: 1.303639
Step-by-step explanation:
The t-score for a level of confidence 
is given by :_
, where df is the degree of freedom and 
is the significance level.
Given : Level of significance : 
Then , significance level : 
Sample size : 
Then , the degree of freedom for t-distribution: 
Using the normal t-distribution table, we have
Thus, the t-score should be used to find the 80% confidence interval for the population mean =1.303639
Answer:
(a) 
(b) 
Step-by-step explanation:
(a) 
can also be written as 
x 
the = ± y
Therefore :
= ±
since it was given that y < 0 , then the factor will be
(b) 
can also be written as : 
x
Therefore , one of the factor is
Answer:
(0, - 7 )
Step-by-step explanation:
Under a reflection in the x- axis
a point (x, y ) → (x, - y ), thus
(0, 7 ) → (0, - 7 )
Well lets see. if you're being specific about the rigor, then the period means that <span>cos(2Π÷3(x+α))=cos(2Π÷3(x))</span>Therefore this gives <span>2π÷3α=2π</span>so α = 3.
Hope this can help you
