Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)
Which methods could you use to calculate the x-coordinate of the midpoint of
a horizontal line segment with endpoints at (0,0) and (20, 0)?
Check all that apply.
C. Count by hand
Answer:
No, the following expression is not a difference of squares. Binomial can not be factored as the difference of two perfect squares. 3 is not a square.
Step-by-step explanation:
Factor
15x^2 - 25
(15x)^2(-5)^5
Divide by 3 and factor
5(3x^2-5)
"Theory:
A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)
Proof : (A+B) • (A-B) =
A2 - AB + BA - B2 =
A2 - AB + AB - B2 =
A2 - B2
Note : AB = BA is the commutative property of multiplication.
Note : - AB + AB equals zero and is therefore eliminated from the expression."
I put a picture to help u understand.