I dont know man...im tryna answer questions so i can ask mine :(
Answer:
Step-by-step explanation:
Answer E is the only one that is close
Answer:
x = 1/5
y = 6
Step-by-step explanation:
System:
{5x + y = 7
{20x + 2 = y
First equation:
5x + y = 7 -> y = -5x + 7
Plug into second equation:
20x + 2 = -5x + 7
Subtract 2 from both sides:
20x = -5x + 5
Add 5x to both sides:
25x = 5
Divde both sides by 25:
x = 5/25 -> 1/5
~~~~~~~~~~~~~~~~~~~~~~~~~~~`
Come back to the first equation:
5x + y = 7
Plus in our x:
5(1/5) + y = 7
Multiply:
1 + y = 7
Subtract 1 from both sides:
y = 6
Hope this helps, have a nice day! :D
Answer:
z≈3.16
p≈0.001
we reject the null hypothesis and conclude that the student knows more than half of the answers and is not just guessing in 0.05 significance level.
Step-by-step explanation:
As a result of step 2, we can assume normal distribution for the null hypothesis
<em>step 3:</em>
z statistic is computed as follows:
z=
where
- X is the proportion of correct answers in the test (
) - M is the expected proportion of correct answers according to the null hypothesis (0.5)
- p is the probability of correct answer (0.5)
- N is the total number of questions in the test (40)
z=
≈ 3.16
And corresponding p value for the z-statistic is p≈0.001.
Since p<0.05, we reject the null hypothesis and conclude that the student knows more than half of the answers and is not just guessing in 0.05 significance level.