1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Gemiola [76]
2 years ago
15

A $100 pair of headphones is marked down by 10% and you also have a 20% off coupon. What is the final price, before tax?

Mathematics
1 answer:
leva [86]2 years ago
8 0

Answer:

$72

Step-by-step explanation:

100 - 10% = 90

90 - 20% = 72

You might be interested in
What is the equation of the line that passes through (-5, -1) and is parallel to the line y=4x-6?
mr_godi [17]
Hello : 
<span>the equation all lines passes through (-5, -1) is :
y - (-1) = m(x -(-5))   m the slope
if this line parallal </span><span>to the line y=4x-6 so : m= 4  (same slope )
</span><span>the equation of the line that passes through (-5, -1) and is parallel to the line y=4x-6:    is  : 
</span> y+1 =4(x+5)
y = 4x +19

8 0
2 years ago
Translate the phrase into an algebraic expression.<br> The quotient of w and 4
Lady_Fox [76]
W/4 divide the two to find the quotient
4 0
3 years ago
True or false? Which one?
ivolga24 [154]

Answer:

true

hope this helps

have a good day :)

Step-by-step explanation:

5 0
2 years ago
Read 2 more answers
The CPA Practice Advisor reports that the mean preparation fee for 2017 federal income tax returns was $273. Use this price as t
skad [1K]

Answer:

a) 0.6212 = 62.12% probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean.

b) 0.7416 = 74.16% probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean.

c) 0.8804 = 88.04% probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean.

d) None of them ensure, that one which comes closer is a sample size of 100 in option c), to guarantee, we need to keep increasing the sample size.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the z-score of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean \mu and standard deviation \sigma, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean \mu and standard deviation s = \frac{\sigma}{\sqrt{n}}.

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The CPA Practice Advisor reports that the mean preparation fee for 2017 federal income tax returns was $273. Use this price as the population mean and assume the population standard deviation of preparation fees is $100.

This means that \mu = 273, \sigma = 100

A) What is the probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean?

Sample of 30 means that n = 30, s = \frac{100}{\sqrt{30}}

The probability is the p-value of Z when X = 273 + 16 = 289 subtracted by the p-value of Z when X = 273 - 16 = 257. So

X = 289

Z = \frac{X - \mu}{\sigma}

By the Central Limit Theorem

Z = \frac{X - \mu}{s}

Z = \frac{289 - 273}{\frac{100}{\sqrt{30}}}

Z = 0.88

Z = 0.88 has a p-value of 0.8106

X = 257

Z = \frac{X - \mu}{s}

Z = \frac{257 - 273}{\frac{100}{\sqrt{30}}}

Z = -0.88

Z = -0.88 has a p-value of 0.1894

0.8106 - 0.1894 = 0.6212

0.6212 = 62.12% probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean.

B) What is the probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean?

Sample of 30 means that n = 50, s = \frac{100}{\sqrt{50}}

X = 289

Z = \frac{X - \mu}{\sigma}

By the Central Limit Theorem

Z = \frac{X - \mu}{s}

Z = \frac{289 - 273}{\frac{100}{\sqrt{50}}}

Z = 1.13

Z = 1.13 has a p-value of 0.8708

X = 257

Z = \frac{X - \mu}{s}

Z = \frac{257 - 273}{\frac{100}{\sqrt{50}}}

Z = -1.13

Z = -1.13 has a p-value of 0.1292

0.8708 - 0.1292 = 0.7416

0.7416 = 74.16% probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean.

C) What is the probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean?

Sample of 30 means that n = 100, s = \frac{100}{\sqrt{100}}

X = 289

Z = \frac{X - \mu}{\sigma}

By the Central Limit Theorem

Z = \frac{X - \mu}{s}

Z = \frac{289 - 273}{\frac{100}{\sqrt{100}}}

Z = 1.6

Z = 1.6 has a p-value of 0.9452

X = 257

Z = \frac{X - \mu}{s}

Z = \frac{257 - 273}{\frac{100}{\sqrt{100}}}

Z = -1.6

Z = -1.6 has a p-value of 0.0648

0.9452 - 0.0648 =

0.8804 = 88.04% probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean.

D) Which, if any of the sample sizes in part (a), (b), and (c) would you recommend to ensure at least a .95 probability that the same mean is withing $16 of the population mean?

None of them ensure, that one which comes closer is a sample size of 100 in option c), to guarantee, we need to keep increasing the sample size.

6 0
2 years ago
The focus of a parabola is located at (4,0), and the directrix is located at x = –4.
Tanzania [10]
The distance between the focus and directrix is, in this case, 8. Since the directrix is at x= something, the parabola opens sideways, and since the directrix is on the left, to the right. In which case, y^2=p(x), where p is 4 times distance of half of distance between directrix and focus, so the answer is y^2=16x
3 0
3 years ago
Read 2 more answers
Other questions:
  • 50 POINTS
    10·2 answers
  • Given the coordinates S(-3,6) and T(4, -8). Find the equation of the line that passes through the two points and write the equat
    15·1 answer
  • PLZ HELP HELP WITH ALL PART REALLY NEED HELP WITH THIS!!
    15·1 answer
  • What is 6(4p - 2) + 2 (5p + 2)
    10·1 answer
  • Please help me with my math ;-;
    9·1 answer
  • The length of a rectangular rug is 4 less than twice its width. The perimeter of the rug is 40 feet. What is the area of the rug
    10·1 answer
  • Solve UW. how do I get the answer?
    11·2 answers
  • Seventeen lines drawn in a plane, with no three concurrent and no two parallel, divide the plane into
    9·2 answers
  • Please help me now help me nowww please
    8·1 answer
  • The functions f(x) and g(x) are shown on the graph.
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!