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.
Answer:
82.88%
Step-by-step explanation:
Given that:
Mean (μ) = 16.7 pounds
Standard deviation (σ) = 3.8 pounds
Number of pounds eaten = 11.5 = x
P(11.5 ≥ x ≤11.5)
P(x ≤ 11.5) :
Zscore = (x - μ) / σ
Zscore = (11.5 - 16.7) / 3.8
Zscore = - 5. 2 / 3.8
Zscore = −1.368421
P(Z ≤ - 1.3684) = 0.085593 (Z probability calculator)
P(x ≥ 11.5) ;
Zscore = (x - μ) / σ
Zscore = (11.5 - 16.7) / 3.8
Zscore = - 5. 2 / 3.8
Zscore = −1.368421
P(Z ≥ - 1.3684) = 0.91441 (Z probability calculator)
P(Z ≥ - 1.3684) - P(Z ≤ - 1.3684)
0.91441 - 0.085593 = 0.828817
0.828817 * 100% = 82.88%
Answer:
x = 4
Step-by-step explanation:
4(2x+9) = 68
8x+36 = 68
8x = 68 - 36
x = 4