Answer:
Step-by-step explanation:
Usually, this wording means the decrease is proportional to the current price, characteristic of an exponential function.
__
The decay factor is 1-(decay rate), so is 1-0.15 = 0.85. After 3 years, the value has been multiplied by this factor 3 times:
$50×0.85³ ≈ $30.71 . . . . cost in 3 years
_____
<em>Comment on percent per year</em>
Less often, the indicated decrease is intended to be <em>that percentage of the original price</em>. The result is that the price decreases by a constant amount each year, a linear decrease. This condition most often arises in conjunction with figuring depreciation in value for tax or accounting purposes.
The upshot is that you always need to be careful to understand what the base of a percentage is intended to be.
Answer:
y=-3x+9
Step-by-step explanation:
y=mx+b
m=slope
b=y-intercept
Answer:
The margin of error is multiplied by 
Step-by-step explanation:
margin of error (ME) from the mean can be calculated using the formula
ME=
where
- z is the corresponding statistic of the given confidence level
- s is the standard deviation of the sample (or of the population if it is known)
Since margin of error is proportional with inverse of 
,
if we cut the sample size in half, the margin of error is multiplied by .
Answer: ∠REA = 53°
Step-by-step explanation:
Since ∠BEA = 71°, set both angle measures equal to that.
2x + 5x + 8 = 71
Solve for x. First, combine like terms:
7x + 8 = 71
Then, subtract 8 from both sides:
7x = 63
Divide both sides by 7:
x = 9
Now, plug x into ∠REA:
∠REA = 5x + 8
∠REA = 5(9) + 8
∠REA = 45 + 8
∠REA = 53°
Hope this helps!
