I believe the answer is -25/6 :)
A + c = 824 represents number of tickets to sell
20a + 12c = 13,344 represents cost of each type of ticket
multiply equation 1 by -12 to cancel the variable 'c' and solve for 'a'
-12(a + c = 824)
-12a - 12c = - 9888
20a + 12c = 13,344 add equations together
-----------------------------
8a = 3456 divide both sides by 8
a = 432
To find children's tickets substitute adult numbers back into equation 1.
a + c = 824
432 + c = 824
subtract 432 from both sides
c = 392
adult 432, children 392
Answer:
We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 31.7 milligrams
Sample mean,
= 28.5 milligrams
Sample size, n = 9
Alpha, α = 0.05
Sample standard deviation, s = 2.8 milligrams
First, we design the null and the alternate hypothesis

We use One-tailed t test to perform this hypothesis.
Formula:

Putting all the values, we have

Now,
Since,
We fail to accept the null hypothesis and accept the alternate hypothesis. We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.
Answer:
180’ - 130’
Step-by-step explanation: