Step-by-step explanation:
step 1. this is a trapezoid. the area A = (b1 + b2)h/2 where b1 is the bottom base and b2 is the top base (per se), and h is the height. this formula is the definition of the area of a trapezoid.
step 2. A = (b1 + b2)h/2 = (22 + 9)(5)/2
step 3. A = 31(5)/2 = 155/2 = 77.5in^2.
Answer:
x=9, x=7
Aka x= 9,7
Step-by-step explanation:
Oh goodie, factoring.
I used to be very good at this. My memory is a LITTLE rusty but let's see if we can bust out some penzoil and fix my aching joints (yes I just stole the quote from that terrible show, sue me), shall we?
1. x^2 - 11x + 68 = 5x +5
2. Chuck all the x variables to the left: x^2 - 16x + 68 = 5
3. Get rid of that pesky loser, 5, by subtracting from both sides of the equation (Note that it's important to remember LIKE TERMS, don't try subtracting 5 from 16x, you'll hurt yourself): x^2 - 16x + 68 - 5 = 5 - 5
New equation: x^2 - 16x + 63 = zilch (0)
4. Use AC method to factor: x2+bx+c. AC method definition: a pair of numbers whose product is c and whose sum is b: (x-9)(x-7)=0
5. Solve for x.
Booyah.
Answer:
First question: LCL = 522, UCL = 1000.5
Second question: A sample size no smaller than 418 is needed.
Step-by-step explanation:
First question:
Lower bound:
0.36 of 1450. So
0.36*1450 = 522
Upper bound:
0.69 of 1450. So
0.69*1450 = 1000.5
LCL = 522, UCL = 1000.5
Second question:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
The project manager believes that p will turn out to be approximately 0.11.
This means that 
95% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
The project manager wants to estimate the proportion to within 0.03
This means that the sample size needed is given by n, and n is found when M = 0.03. So
Rounding up
A sample size no smaller than 418 is needed.
Graph A is the correct answer tell me if you need a step by step explanation
<span>Find the wind speed and the plane's airspeed.
:
Let s = speed of the plane in still air
Let w = speed of the wind
then
(s-w) = plane speed against the wind
and
(s+w) = plane speed with the wind
:
Change 3 3/8 hrs to 3.375 hrs
:
The trips there and back are equal distance, (1890 mi) write two distance equations
dist = time * speed
:
3.375(s-w) = 1890
3.0(s + w) = 1890
:
It is convenient that we can simplify both these equations:
divide the 1st by 3.375
divide the 2nd by 3
resulting in two simple equations that can be used for elimination of w
s - w = 560
s + w = 630
----------------adding eliminates w, find s
2s = 1190
s =
s = 595 mph is the plane speed in still air
Find w
595 + w = 630
w = 630 - 595
w = 35 mph is the wind spee</span>
