Answer:
C) 2+7i is the correct answer.
Step-by-step explanation:
simplify by combining the real and imaginary parts of each expression. in this question, the variable i represents an imaginary number.
The correct interpretation of the p-value is given by:
B If the average battery life really is 5 hours, then a sample of 10 observations having a sample mean of 4.25 hours or lower would only occur about 3.8% of the line.
<h3>How to find the p-value of a test?</h3>
It depends on the test statistic z, as follows:
- For a left-tailed test, it is the area under the normal curve to the left of z, which is the p-value of z.
- For a right-tailed test, it is the area under the normal curve to the right of z, which is 1 subtracted by the p-value of z.
- For a two-tailed test, it is the area under the normal curve to the left of -z combined with the area to the right of z, hence it is 2 multiplied by 1 subtracted by the p-value of z, which means that the p-value for a two-tailed test is twice the p-value of a one-tailed test.
In this problem, a left-tailed test is used, as we are testing if the mean is less than 5 hours.
The sample mean from the 10 times was of 4.25, and the p-value is of 0.038, which means that the area to the left of Z under the normal curve is of 0.038, that is, a sample mean of 4.25 hours or lower would only occur about 3.8% of the line, hence option B is correct.
You can learn more about p-values at brainly.com/question/13873630
Answer
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Step-by-step explanation:
