A. The point estimate of μ1 − μ2 is calculated using the value of x1 - x2, therefore:
μ1 − μ2 = x1 – x2 =
7.82 – 5.99
μ1 − μ2 = 1.83
B. The formula for
confidence interval is given as:
Confidence interval
= (x1 –x2) ± z σ
where z is a value
taken from the standard distribution tables at 99% confidence interval, z =
2.58
and σ is calculated
using the formula:
σ = sqrt [(σ1^2 /
n1) + (σ2^2 / n2)]
σ = sqrt [(2.35^2 /
18) + (3.17^2 / 15)]
σ = 0.988297
Going back to the
confidence interval:
Confidence interval
= 1.83 ± (2.58) (0.988297)
Confidence interval
= 1.83 ± 2.55
Confidence interval
= -0.72, 4.38
B.) 10 The length of the board is 7×12 = 84
the largest number of 15 inch pieces that
jeremy can cut is 5. 84÷15 is a quotient of
5 with a remainder of 9. 5×5=10
The two-way table is attached.
We know that 63 people took the survey, and 22 of them were left-handed. This means that 63-22=41 of them are right handed.
Out of the 63 total, 37 are left brain dominant; this means that 63-37=26 are right brain dominant.
Of the 26 that are right brain dominant, 21 are right handed; this means 26-21=5 are left handed.
Of the 22 left-handed people, 5 are right brain dominant; this means 22-5 = 17 are left brain dominant.
Of the 37 left brain dominant people, 17 are left handed; this means 37-17=20 are right handed.
You can figure the line for each pair of points, or you can try the points in the equation you have and see which are on the line.
First answer: x=1, y=-5×1 +4 = -1 . . . not 9. (1, 9) is not a point on the line
Second answer: x=2, y=-5×2 +4 = -6 . . . not -14. (2, 14) is not a point on the line
Third answer: (see the calculation for the first answer) . . . -1 ≠ 1. (1, 1) is not a point on the line
Fourth answer: (see the calculation for the second answer) We know that (2, -6) is on the given line. Checking (4, -16), we find it is as well.
The appropriate choice is the 4th answer:
... a line passing through the points (2, -6) and (4, -16)