Given:
Sample size, n = 40
Sample mean, xb = $6.88
Population std. deviation, σ = $1.92 (known)
Confidence interval = 90%
Assume normal distribution for the population.
The confidence interval is
(xb + 1.645*(σ/√n), xb - 1.645*(σ/√n)
= (6.88 + (1.645*1.92)/√40, 6.88 - (1.645*1.92)/√40)
= (7.38, 6.38)
Answer: The 90% confidence interval is (7.38, 6.38)
The answer is
domain-1
range-5
The answer is 13.
You can evaluate this by substituting x for 5 in the expression.
4x-7
4(5)-7
20-7
13
So solve for the equations of the lines
y=mx+b
m=slope
b=y intercept
line 1=
(-4,5)
(0,2)
(x,y)
slope=(y1-y2)/(x1-x2)
x1=-4
y1=5
x2=0
y2=2
subsitute
(5-2)/(-4-0)=3/-4=-3/4
slope=-3/4
subsitute
y=-3/4x+b
subsitute one of the points
(0,2)
x=0 and y=2 is one solution
2=-3/4(0)+b
2=0+b
2=b
the equation is y=-3/4x+2
other line
(0,5)
(4,2)
x1=0
y1=5
x2=4
y2=2
sybsitute
(5-2)/(0-4)=3/-4=-3/4
slope=-3/4
subsitute
y=-3/4x+b
now subsitute one of the points to solve for b
(0,5)
x=0 and y=5 is one solution
5=-3/4(0)+b
5=0+b
5=b
y=-3/4x+5
so we have the lines/equations
y=-3/4x+2 and y=-3/4x+5
(at this point we can see that since slopes are the same and the y intercepts are different, they are paralell and therefor have 0 solutions, but for those who don't know paralellline thingie read on)
solve for common (x,y)
y=-3/4x+2
y=-3/4x+5
subsitute
-3/4x+2=y=-3/4x+5
-3/4x+2=-3/4x+5
subtract 2 from both sides
-3/4x=-3/4x+5
add 3/4x to both sides
0=5
fasle
there are no solutions
the answer is A: 0 solutions
0.37
1 2/3 divided by 4 1/2
