The 95% confidence interval can be calculated using the formula:
CI = X̄ ± Z * (σ / √n)
Where:
X̄ = sample mean = $18,412
Z = Z-score for a 95% confidence interval = 1.96
σ = sample standard deviation = $993
n = sample size = 187
Plugging in the values:
CI = $18,412 ± 1.96 * ($993 / √187)
CI = $18,412 ± 1.96 * ($72.45)
CI = $18,412 ± $142.18
Therefore, the 95% confidence interval is $18,269.67–$18,554.33
So, the correct answer is:
$18,269.67–$18,554.33
A random sample of 187 adults was selected from a population of a town to determine their average savings account balance. The sample mean was equal to $18,412, with a sample standard deviation of $993. What is the 95 percent confidence interval?(1 point) Responses $18,269.67–$18,554.33 $18,269.67–$18,554.33 $806–$1,180 $806–$1,180 $18,225–$18,599 $18,225–$18,599 $17,419–$19,405
1 answer
1 answer