A) The given equation has no solution. The absolute value cannot be negative, but must be -9 in order for the equation to be satisfied.
b) |x -7| = 2 . . . . . . . the equation
Solution 1:
-2 = x -7
5 = x . . . . . . add 7
Solution 2
x -7 = 2
x = 9 . . . . . . add 7
The two numbers are {5, 9}
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
Put x=-2 in x-y=-2
-2-y=-2
-y=0
y=0
x=-2
that's your answer.
