192k views
5 votes
There were 324 adults surveyed. Among the participants, the mean number of hours of sleep each night was 7.5 and the standard deviation was 1.6. The margin of error, assuming a 95% confidence level, is approximately . Round to the nearest hundredth

2 Answers

3 votes
0.17 sense you have to round it to the nearest hundreth


User Axelfran
by
8.4k points
4 votes

Answer with explanation:

Total Population Being Surveyed = 324

Mean of the Population = 7.5

Standard Deviation =1.6

Margin of Error is given by the formula


=Z_{\text{value at 95 percent confidence interval}}* \frac{\text{Standard deviation}}{\sqrt{\text{Sample size}}}\\\\=1.96 * (1.6)/(√(324))\\\\=1.96* (1.6)/(18)\\\\=(3.136)/(18)\\\\=0.1742

Marginal of Error = 0.17 (approx)

Mean =7.5

Confidence Interval for a population when Z score at 95% is calculated =Mean
\pm margin of error

=that is between ,7.50 +0.17 to ,7.50 -0.17

=Between ,7.33 to 7.67

User Michael Andorfer
by
8.0k points