Karen can paint a wall in 2.5 hours. Stephanie takes 1.25 hours to paint the same size wall. How many minutes will it take for K
1 answer:
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Answer:
The 95% confidence interval for the population mean rating is (5.73, 6.95).
Step-by-step explanation:
We start by calculating the mean and standard deviation of the sample:
We have to calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=6.34.
The sample size is N=50.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 95% confidence interval for the mean is (5.73, 6.95).
Answer:
C
Step-by-step explanation:
These sides are in a ratio:
Therefore:
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.