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9 votes
Swapna gathered data on the number of page views for each of her blog posts. For her 40 latest posts, she found a sample mean of 358 with a population standard deviation of 54.3. What is the approximate 95% confidence interval for her page views? A.

344 and 372
B.
341 and 375
C.
356 and 360
D.
336 and 380

User Cartant
by
5.1k points

2 Answers

9 votes

Final answer:

The approximate 95% confidence interval for the number of blo-g page views is between 341.18 and 374.82, with the closest answer being Option B: 341 and 375.

Step-by-step explanation:

To approximate the 95% confidence interval for the number of page views on Swapna's blo-g posts, we use the formula for confidence intervals when the population standard deviation is known. Given that the sample mean (X) is 358, the population standard deviation (σ) is 54.3, and the sample size (n) is 40, we can find the confidence interval using the z-score associated with the 95% confidence level, which is 1.96 for a two-tailed test.

Confidence Interval = X ± z × (σ/√n)
Using the given data, the calculation is as follows:
Confidence Interval = 358 ± 1.96 × (54.3/√40)
Confidence Interval = 358 ± 1.96 × 8.58
Confidence Interval = 358 ± 16.82
Therefore, the confidence interval is approximately between 341.18 and 374.82.

The closest answer that matches our calculation is Option B: 341 and 375.

Note that some of the reference information provided such as sample sums and other means seem to be mis-aligned with the question or provide extra-neous data not necessary for calculation.

User Shreyas Patil
by
4.4k points
3 votes

Answer:

c

Step-by-step explanation: