Answer:
C. [21.80, 22.80]
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 22.3 - 0.5 = 21.8 hours.
The upper end of the interval is the sample mean added to M. So it is 22.3 + 0.5 = 22.8 hours
So the correct answer is:
C. [21.80, 22.80]
Answer:
f(2) = -6
General Formulas and Concepts:
Order of Operations: BPEMDAS
Substitution and Evaluation
Step-by-step explanation:
<u>Step 1: Define</u>
f(x) = -2x² + 4x - 6
f(2) is x = 2
<u>Step 2: Solve</u>
- Substitute: f(2) = -2(2)² + 4(2) - 6
- Exponents: f(2) = -2(4) + 4(2) - 6
- Multiply: f(2) = -8 + 8 - 6
- Add: f(2) = -6
Answer:
x= -1/3
x = -7
Step-by-step explanation:
9x^2 +66x+21 = 0
a=9 b=66 c=21
quadratic formula
x=(-b +/- square root of (b^2 – 4ac))/(2a)
x = (-66 +/- square root of (66^2 -4*9*21))/(2*9)
x = (-66 +/- square root of (4356 -756))/(18)
x = (-66 +/- square root of (3600))/(18)
x = (-66 +/- 60)/18
split the fraction
(-66 +/- 60)/18 = -6/18 and -126/18 because of the +/-
x = -6/18 x = -126/18
x = -1/3 x = -7
Answer:
x = 10
Step-by-step explanation:
2x + 5 = 25
-5
2x = 20
/2
x = 10
Answer:
Step-by-step explanation:
Used a graphing calculator,
hope this helps.
