A is located, as you look A is past -2 almost hitting -3 making the mark 2.8 so the answer is A
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
Answer:
2.5 x
miles
Step-by-step explanation:
We are given that 1 light year ≈ 5.9 x
miles so:
- 4.3 x 10² light year · <u>5.9 x </u>
<u> miles </u> - 1 light year
Multiply 4.3 an 5.9 and round to 2 significant digits then add the exponents:
≈25 x 
This is not the scientific notation since the number is not between 0 and 10 so we move the decimal point by 1 place to the left. We then add 1 to the exponent to obtain the final answer:
≈ 2.5 x
miles