Answer:
Step-by-step explanation:
Let
be the cost of renting from Mozart's Music Store for
years, and
be the cost of renting from Bach's Music Store for
years.
From the problem statement, we can come up with the following equations:


Plugging in
for each equation, we can get the answer:







From this, we can see that the value is equal for both stores.
We're given the algebraic expression 2x^2 - 2z^4 + y^2 - x^2 + z^4
By hypothesis, x = -4, y = 3 and z = 2
Let's replace each letter by its given value:
2x^2 - 2z^4 + y^2 - x^2 + z^4
2(-4)^2 - 2(2)^4 + (3)^2 - (-4)^2 + (2)^4
(2*16) - 2*16 + 9 - 16 + 16
32 - 32 + 9 - 16 + 16
9
So wrong. The correct answer is not -3, but 9.
Hope this helps! :D
Answer:
option (a) It will be closer to 30 than to 20
Step-by-step explanation:
Data provided in the question:
For sample 1:
n₁ = 10
variance, s₁² = 20
For sample 2:
n₂ = 15
variance, s₂² = 30
Now,
The pooled variance is calculated using the formula,

on substituting the given respective values, we get

or
= 26.0869
Hence,
the pooled variance will be closer to 30 than to 20
Therefore,
The correct answer is option (a) It will be closer to 30 than to 20
21,800,000 rounded to the nearest million = 22,000,000
So average is of the first 6 tests is 82 well that means
(test1 + test2+ test3+ test4 + test5+test6)/6 = 82
so now let do some cross multiplliying
test1 + test2 + test3 + test 4 + test5 +test6 = 82*6
test1 + test2 + test3 + test 4 + test5 +test6 = 492
now lets see if we can find that 7th test score
(test1 + test2 + test3 + test4 + test5 +test6 + test7)/7 = 80.5
So look we found test1 + test2 + test3 + test4 + test5 +test6 to be 492 so lets substitute.
(492 + test7 )/7 = 80.5
test7 = (80.5*7)-492 = 71.5