1.004 * 10^5
all scientific notation equations have to be a number greater than 1 but less than 10
then multiplied by 10 to the power of (move the decimal point to the right however many times you need, in this case 5) :)
Answer:
Step-by-step explanation:
x-y=7
-3x+9y=-39
Divide the second equation by 3
-x +3y = -13
Add this to the first equation
x-y=7
-x +3y = -13
----------------------
0x +2y = -6
Divide by 2
2y/2 = -6/2
y = -3
Now find x
x-y = 7
x -(-3) = 7
x+3 = 7
Subtract 3 from each side
x = 4
(4,-3)
Or by substitution
x-y=7
solve for x
x = 7+y
-3x+9y=-39
Substitute y+7 in for x
-3(7+y) +9y = -39
Distribute
-21 -3y +9y = -39
Combine like terms
-21 +6y = -39
Add 21 to each side
6y = -18
Answer:
B
Step-by-step explanation:
Given that r is inversely proportional to s then the equation relating them is
r = 
← k is the constant of proportion
To find k use the condition r = 16 when s = 3
k = rs = 16 × 3 = 48
r = 
← equation of variation → B
Answer:
We accept H₀ . We don´t have enough evidence to express the publisher claim is not true
Step by Step explanation:
We must evaluate if the mean of the price of college textbooks is different from the value claimed by the publisher
n < 30 then we must use t - distrbution
degree of freedom n - 1 df = 22 - 1 df = 21
As the question mentions " different " that means, a two-tail test
At 0,01 significance level α = 0,01 α/2 = 0,005
and t(c) = 2,831
Test Hypothesis
Null Hypothesis H₀ μ = μ₀
Alternative hypothesis Hₐ μ ≠ μ₀
To calculate t(s)
t(s) = ( μ - μ₀ ) /σ/√n
t(s) = ( 433,50 - 385 ) / 86,92 / √22
t(s) = 2,6171
Comparing t(c) and t(s)
t(s) < t(c)
Then t(s) is in the acceptance region we accept H₀. We don´t have enough evidence to claim that mean price differs from publisher claim
