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)
Answer:
x = 8*root3
y = 16
Step-by-step explanation:
You can use tangent and cosine of 60° to find x and y, BUT THERE'S A SHORTCUT. You pointed out that its a 30°-60°-90° triangle. That is a special right triangle. Here's the shortcut:
the longest side (hypotenuse) is double the shortest side. We have an 8 on the shortest side, so the hypotenuse (longest side) is 16. This ALWAYS works for 30°-60°-90° triangles!
Another shortcut:
The longer leg is the shorter leg × root3.
This ALWAYS works on 30°-60°-90° triangles.
So on your triangle, the short side is 8, that means the longer leg is 8×root3.
ta-daaaa!
1. Divide 95 million by the amount of days in a year
95 million divided by 365 = $260273.97
$260273.97 is made in a day.
Multiply it by 9.
So, 260273.97 x 9 = $2342465.75
$2342465.75 is made in 9 days.
