To find sales tax on something, multiply the percent of the tax by the price of the item.
The answer is 7x+7/x^2+3x-10
Answer:

Step-by-step explanation:
we know that
The simple interest formula is equal to
where
A is the Final Investment Value
P is the Principal amount of money to be invested
r is the rate of interest
t is Number of Time Periods
in this problem we have
The inequality that represented this situation is

substitute the values and solve for t


![t \leq [(7,020/4,500)-1]/0.03](https://tex.z-dn.net/?f=t%20%5Cleq%20%5B%287%2C020%2F4%2C500%29-1%5D%2F0.03)

Answer:
Mean=685
Variance=36.7
Step-by-step explanation:
The mean of uniform discrete distribution can be expressed as the average of the boundaries
mean=( b+a)/2
The variance of uniform discrete distribution can be expressed as the difference of the boundaries decreased by 1 and squared, decreased by 1 and divided by 12.
σ²=[(b-a+1)^2 - 1]/12
We were given the wavelength from from 675 to 695 nm which means
a= 675, b= 695
We can now calculate the mean by using the expresion below
mean=( b+a)/2
Mean=( 675 + 695)/2
=685
The variance can be calculated by using the expression below
σ²=[(b-a+1)^2 - 1]/12
σ²=[(695-675+1)^2 -1]/12
σ²=440/12
σ²=36.7
Therefore, the the mean and variance, of the wavelength distribution for this radiation are 685 and 36.7 respectively