<u>Let's solve this problem step-by-step</u>
<u>Let's set</u>:
2x + 6y = 36 -- equation 1
x + 4y = 20 -- equation 2
(equation 2) * 2
2x + 8y = 40 -- equation 3
(equation 3) - (equation 1)
2y = 4
y = 2 -- equation 4
Plug (equation 4)'s value of y into (equation 2)
x + 4(2) = 20
x = 20 - 8
x = 12
<u>Thus x = 12 and y = 2</u>
<u>Let's check, by substituting these values</u>
<u>Answer: x = 12 and y = 2</u>
Hope that helps!
Answer:
5/2
Step-by-step explanation:
duh
Answer:
\pi
Step-by-step explanation:
Answer:
144
Step-by-step explanation:
-12 x -3 = 36
4 x 36 = 144
Answer:
Roland is right, he can be 95% sure that average gas prices have gone up since the same time last year.
Step-by-step explanation:
Let μ be average gas price around Syracuse.
Then hypotheses are:
μ = $2.68
μ > $2.68
Then test statistic can be calculated as:
z=
where
- X is the Roland's calculated average gas prices of 50 gas stations ($2.74)
- M is the average average gas prices in the entire of Syracuse last year
- s is the standard deviation ($0.11)
Then z=
≈ 3.86
Since P-value of test statistic ≈ 0.00006 <0.05 (significance level), we can reject the null hypothesis.
