Answer: The critical value for a two-tailed t-test = 2.056
The critical value for a one-tailed t-test = 1.706
Step-by-step explanation:
Given : Degree of freedom : df= 26
Significance level : 
Using student's t distribution table , the critical value for a two-tailed t-test will be :-

The critical value for a two-tailed t-test = 2.056
Again, Using student's t distribution table , the critical value for a one-tailed t-test will be :-

The critical value for a one-tailed t-test = 1.706
Answer:
178
Step-by-step explanation:
Use Pythagorean Theorem to find the Hypotenuse
30^2+72^2=78^2
Use perimeter formula
a+b+c
38+72+30
The area is 289.22 units squared
The value of the expression in the form a(x+b)^2 is 1.5(x+2)^2 - 4
<h3>Vertex Form of a quadratic expression</h3>
Given the quadratic expressions
1.5x^2+6x+......
1.5(x^2 + 4x)
Using the completing the square method
The coefficient of x = 4
Half of the coefficient = 4/2 = 2
The square of the result = 2^2 = 4
The equation is expressed as:
f(x) = 1.5(x^2+4x+ 4) - 4
f(x) = 1.5(x+2)^2 - 4
Hence the value of the expression in the form a(x+b)^2 is 1.5(x+2)^2 - 4
Learn more on completing the square method here: brainly.com/question/1596209
Look at deonomators
assuming that the deonomenators are 5x+15y and 2x+6y
find their LCM
factor
5x+15y=5(x+3y)
2x+6y=2(x+3y)
LCM=10(x+3y)=10x+30y
multiply 2/(5x+15y) by 2/2=4/(10x+30y)
multiply 1/(2x+6y) by 5/5=5/(10x+30y)
if we add them
9/(10x+30y)