1) The formula used for determining the confidence interval is
Sample mean +/- Critical value (or z-score corresponding to 90% confidence) * Standard
error of mean
8439 +/- 1.645 * 100/sqrt 25
8439 +/- 1.645 * 20
8439 +/- 32.9
2) The only difference in this case is finding the critical value i.e., z-score corresponding to 92% confidence which is 1.75 approximately
Then the confidence interval is
8439 +/- 1.75 * 100/sqrt 25
8439 +/- 1.75 * 20
8439 +/- 35
Lower limit is 8439 - 35 = 8404
The upper limit is 8439 + 35 = 8474
Answer: 16
Step-by-step explanation:
B that’s the right answer
Answer:
The number of cats at the shelter on Friday was 20.
Step-by-step explanation:
Hi there!
Let "x" be the number of cats and "y" the number of dogs.
The shelter spends $2 per cat and $7 per dog. If the total expenses on Friday was $82, then, two times the number of cats plus seven times the number of dogs is equal to 82:
2x + 7y = 82
We also know that the total number of cats and dogs was 26. Then, the number of cats plus the number of dogs is equal to 26:
x + y = 26
Let´s solve this equation for y and replace it in the first equation
y = 26 - x
Then:
2x + 7(26 - x) = 82
Apply distributive property:
2x + 182 - 7x = 82
Subtract 182 to both sides of the equation:
-5x = -100
divide both sides of the equation by -5
x = 20
The number of cats at the shelter on Friday was 20.
Have a nice day!
