What? Can you attach a photo?
1.50x + 450 = 3x
450 = 3x - 1.50x
450 = 1.50x
450/1.50 = x
300 = x
300 copies must be sold to break even
Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)
Because this is a triangle and we know that we can use the Pythagorean Theorem to find the hypotenuse we just plug in the numbers. But because you have the hypotenuse already you will subtract the leg from the hypotenuse.
A^2+B^2=C^
16^2+B^2=20^2
256+B^2=400 subtract 256 from both sides
B^2=144 now take the square root of both sides
B=12
The second leg is 12 cm long. Your answer is B, the second answer.
1 DOC
2 BOC
3 EOC
4 AOD
5 AOC
