Answer:
a. [ 0.454,0.51]
b. 599.472 ~ 600
Step-by-step explanation:
a)
Confidence Interval For Proportion
CI = p ± Z a/2 Sqrt(p*(1-p)/n)))
x = Mean
n = Sample Size
a = 1 - (Confidence Level/100)
Za/2 = Z-table value
CI = Confidence Interval
Mean(x)=410
Sample Size(n)=850
Sample proportion = x/n =0.482
Confidence Interval = [ 0.482 ±Z a/2 ( Sqrt ( 0.482*0.518) /850)]
= [ 0.482 - 1.645* Sqrt(0) , 0.482 + 1.65* Sqrt(0) ]
= [ 0.454,0.51]
b)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.05 is = 1.96
Samle Proportion = 0.482
ME = 0.04
n = ( 1.96 / 0.04 )^2 * 0.482*0.518
= 599.472 ~ 600
Answer:
1. True
2. False
3.-48
4. This relation could also be represented as {(-1, 1), (0, -2), (3, 1), (4, -1)}
5. can you please put the points in parentheses becasue I cannot tell which pair is which. If you rephrase it I will comment the anwer
Step-by-step explanation:
The answer is 47 minutes.
You basically imagine this: Debra has a phone card for $30. She used x minutes every 16 cents. You end up with $22.48.
30 - (0.16x) = 22.48
You can basically graph that equation and the x-intercept will show you your answer. x = 47
The answer is 120 feet.
The area of the field (A) is:
A = w · l (w - width, l - length)
It is known:
A = 12,000 ft²
l = w - 20
So, let's replace this in the formula for the area of the field:
12,000 = w · (w - 20)
12,000 = w² - 20
⇒ w² - 20w - 12,000 = 0
This is quadratic equation. Based on the quadratic formula:
ax² + bx + c = 0 ⇒

In the equation w² - 20w - 12,000 = 0, a = 1, b = -20, c = -12000
Thus:

So, width w can be either

or

Since, the width cannot be a negative number, the width of the field is 120 feet.