Answer:
2√21
Step-by-step explanation:
1) Simplify.
√84
2) Simplify √84 to 2√21.
2√21
.74 is the answer rounded to nearest hundredth.
I think the group 2 survey is likely to be biased towards people who are not too keen on zoos since all the values are small.
From group 1 and 3 the mean number of visits are
(4 + 10 + 6 + 3 + 8 + 7 + 9 + 3 + 4 + 7) / 10
= 61/10
mean = 6
A is the correct answer
pls mark me as the brainliest
Answer:
Step-by-step explanation:
We want to determine a 95% confidence interval for the population mean.
Number of sample, n = 56
Mean, u = 645 hours
Standard deviation, s = 31 hours
For a confidence level of 95%, the corresponding z value is 1.96.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
645 ± 1.96 × 31/√56
= 645 ± 1.96 × 4.142
= 645 ± 8.12
The lower end of the confidence interval is 645 - 8.12 =636.88
The upper end of the confidence interval is 645 + 8.12 =653.12
Therefore, with 95% confidence interval for the population mean life of fluorescent light bulbs is between 636.88 hours and 653.12 hours
