Answer:
Step-by-step explanation:
Since population std deviation is not known, we use t critical value for testing of hypothesis.
a) 90% conf level when n =28
df = 27, t critical = 1.706
b) 95% 28
df =27 and t critical = 2.052
c) 90% and 15
df =14 and t critical = 1.761
d) 95% and n =15
df =14: t critical = 2.145
Answer:
40
Step-by-step explanation:
Let n represent the integer. Then the increase can be written as ...
n + (-12) = 28
We can add 12 to both sides of this equation:
n + (-12) + (+12) = 28 +12
n + 0 = 40 . . . . . . -12 and 12 total to zero; 28 and 12 total to 40.
n = 40
The integer is 40.
Answer:
C. Multiply 3 by 18
Step-by-step explanation:
Susan reads:
1 page in 3 mins
So,
1 page = 3 mins
<u><em>If we want the time for 18 pages, we would multiply both sides by 18</em></u>
So,
18 pages = 3×18 mins
18 pages = 54 mins
She has $55. She spent $22.50 on rides so now she has $32.50 . Then she spends $14.25 on lunch and snack so now she has $18.25.
A. would be wrong because Courtney IS correct, she has $18.25 left.
C. is also wrong because, again, Courtney IS correct.
So the only option left is B and it explains why Courtney is correct.
Option B is the correct answer.
Hope this helps.
