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)
-18-(-12)=-6
Since there is two negative sign, it turns into positive meaning the -12 becomes positive 12 and the -18 stays same. So -18+12=-6 because 18 is bigger than 12 and it's negative so the final answer should be negative.
Hint: when you see two negative sign just turn them into plus sign.
For #8, it's approximately 2.5
First step: you got to add y to both sides in the math problem Ex: 15x - y + y < 12 + y
Second step: simplify 15x < 12 + y
Third Step: This you got to divide both sides by 15 like this: 15x/15 < 12/15 + y/15
Last and Fourth step: Simplify and thats your answer x < 12 + y/15
Answer:
Ratio of blue fish in the small tank to the red fish in large tank is 10 : 6279
Step-by-step explanation:
Let the number of red fish and blue fish in the large tank are x and y respectively.
Similarly ratio of red fish and blue fish in the small tank are x' and y' respectively.
Since in each tank ratio of the red fish to blue fish is 333 : 444
That means x : y = 333 : 444
Or 
⇒ 
⇒ y = 
--------(1)
Similarly x' : y' = 333 : 444
⇒ 
⇒ 
⇒ x' = 
------(2)
Ratio of the fish in large tank to the fish in small tank is 464646 : 555
So (x + y) : (x' + y') = 464646 : 555
Now we replace the values of x and y' from equation (1) and equation (2)
Therefore, ratio of blue fish in the small tank to the red fish in large tank is 10 : 6279
