Answer:
( $74.623, $83.777)
The 90% confidence interval is = ( $74.623, $83.777)
Critical value at 90% confidence = 1.645
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = $79.20
Standard deviation r = $10.41
Number of samples n = 14
Confidence interval = 90%
Using the z table;
The critical value that should be used in constructing the confidence interval.
z(α=0.05) = 1.645
Critical value at 90% confidence z = 1.645
Substituting the values we have;
$79.20+/-1.645($10.42/√14)
$79.20+/-1.645($2.782189528308)
$79.20+/-$4.576701774067
$79.20+/-$4.577
( $74.623, $83.777)
The 90% confidence interval is = ( $74.623, $83.777)
When rounding, look to the next place to the right of what you are rounding to... for example if you are rounding to the nearest hundredth, look to the thousandths place to see if the hundredths place rounds up or down. Since your number, 615.44 stops on the hundredths place, the thousandths place is automatically zero, so your number stays the same.
615.44
Answer:
C
Step-by-step explanation:
the decimal would have to move 9 times from the zero position to get to between 5 and 8.
so 5.82 x 10^9