You're right - it's D. Both ratios are equal to 1/2.
Answer:
discount:deduct an amount from (the usual price of something).
tip:give (someone) a sum of money as a reward for a service
markup:the amount added to the cost price of goods to cover overheads and profit.
Sales tax:a tax on sales or on the receipts from sales
Answer:
We need a sample size of at least 369.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
For this problem, we have that:
90% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
How large of a sample size is required?
We need a sample size of at least n.
n is found when 
. So
Rounding up
We need a sample size of at least 369.
Logarithmic differentiation means tAke logarithm of both sides to make the function easier to find the derivative.
y = (sinx)^lnx
ln(y) = ln((sinx)^lnx)
power rule logarithm
ln(y) = ln(x) ln(sinx)
Take derivative
y'/y = ln(sinx)(1/x) + ln(x) cosx/sinx
multiply both sides by y
y' = y( ln(sinx)/x + ln(x)cotx )
remember y = (sinx)^lnx
sub this in for y
y' = (ln(sinx)/x + ln(x)cotx)(sinx)^lnx
