Dora bought a bottle of nail polish that was marked down by 20 percent from its original price of $4.50. Including a 9 percent sales tax, what is the final cost of the bottle of nail polish?

3.82

Step-by-step explanation: Find 80% of 4.50 (4.50 x 0.8=3.60) then find 6% of 3.6 (0.06 x 3.6= 0.216) add 0.216 + 3.6= 3.816 but in money you have to round so the answer is 3.82

1.8

Step-by-step explanation:

$4.50-%20=3.6

3.6- %9=1.8

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;

answer: 270

step-by-step explanation:

you have to times 200 by 1.35 to get your answer