Answer:
20 +/- $6.74
= ( $13.26, $26.74)
The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)
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.
x1-x2 +/- margin of error
x1-x2 +/- z(√(r1^2/n1 + r2^2/n2)
Given that;
Mean x1 = $200
x2 = $180
Standard deviation r1 = $22.50
r2 = $18.30
Number of samples n1 = 60
n2 = 40
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
$200-$180 +/-1.645(√(22.5^2/60 +18.3^2/40)
$20 +/- 6.744449847374
$20 +/- $6.74
= ( $13.26, $26.74)
The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)
Answer:
will make the equation true
Step-by-step explanation:
Given
Required
Which is true for x
We have:
Collect like terms
Solve for x
Step-by-step explanation:
.3f+1 = .2f-4.5
1. Subtract .2f both sides
.1f+1 = -4.5
2. Subtract 1 from both sides
.1f = -5.5
3. Divide .1 both sides
f = -55
To check plug in -55 to all the f’s and both sides should be equal.
Hope this helps!
Answer:
y=1/2x-3
Step-by-step explanation:
Answer:
9 sides
Step-by-step explanation:
7y + 2y = 180
9y = 180
y =20
so, 2y, the exterior angle is 2 x 20 = 40
Divide 360 by 40 = 9
