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
kvv77 [185]
3 years ago
14

John has $20.00 to spend for his mother's birthday. A string of pearls and a pair of pearl earrings costs $25.00. They are on sa

le for 30% off. How much money will John have left?​
Mathematics
1 answer:
Phoenix [80]3 years ago
4 0

Answer:

2.50

Step-by-step explanation:

30% of 25 is 7.50 take that away from 25 gives you 17.50 take that away from 20 gives you 2.50

You might be interested in
Given: f(x) = 8x4 + 2x3 – x + 3 and g(x) = -5x3 + 7x + 2<br> Simplify: f(x) + g(x)
ivolga24 [154]

Answer:

Step-by-step explanation:

8x^4+2x^3-x+3-5x^3+7x+2\\ \\ 8x^4-3x^3+6x+5

4 0
3 years ago
The distribution of weights of United States pennies is approximately normal with a mean of 2.5 grams and a standard deviation o
stich3 [128]

Answer:

a) P(X

b) \bar X \sim N(2.5, \frac{0.03}{\sqrt{10}}=0.00948)

c) P(\bar X

And using a calculator, excel or the normal standard table we have that:

P(Z

d) Figure attached

e) If we don't know the distribution then we can't ensure that the sample mean would be distributed like this:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

And we can't estimate the probabilities on a easy way.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Part a

Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:

X \sim N(2.5,0.03)  

Where \mu=2.5 and \sigma=0.03

We are interested on this probability

P(X

And the best way to solve this problem is using the normal standard distribution and the z score given by:

z=\frac{x-\mu}{\sigma}

If we apply this formula to our probability we got this:

P(X

And we can find this probability on this way:

P(-0.50

Part b

Since the distribution for X is normal then the distribution for the sample mean is:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

\bar X \sim N(2.5, \frac{0.03}{\sqrt{10}}=0.00948)

Part c

P(\bar X

And using a calculator, excel or the normal standard table we have that:

P(Z

Part d

See the figure attached the deviation for the sample mean is lower for this reason we have the pattern in the graph attached.

Part e

If we don't know the distribution then we can't ensure that the sample mean would be distributed like this:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

And we can't estimate the probabilities on a easy way.

4 0
3 years ago
What is this??? 28÷7×4=?
Tanya [424]

Answer: 16

Step-by-step explanation: 28÷7=4

                                             4×4   = 16

7 0
2 years ago
7th grade math!<br><br> Divide 20xy^4z^12 by 4x^3yz^24<br><br> Answer options in picture above.
luda_lava [24]

Answer:third one

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
A framer browwed a sum of rs 10000 from rural development bamk at the rate of 7.5% p.a . if he/she paid an qmount at rs 15250 to
daser333 [38]

Answer:

7

Step-by-step explanation:

can't explain my steps bcuz it was so ez. got it in a second within looking at it.

5 0
3 years ago
Other questions:
  • What is the number of seven hundred thirty-one millon, nine hundred thirty- four thoudand thirty in standered form?
    11·1 answer
  • Roberto is having his house painted. The job takes three days, and he pays the painter the same hourly rate every day. The cost
    11·2 answers
  • What is cos A for this triangle?
    7·1 answer
  • Josh has 12 computer games he received 1\4 of them for his birthday how many computer games did he receive for his birthday
    7·1 answer
  • Explain this please
    7·1 answer
  • Suppose that the function h is defined, for all real numbers , as follows.
    12·1 answer
  • Given: 4n^2 + 25 = -20x, what is the value of the discriminant?
    6·1 answer
  • For c = d (3.14), find c when d = 100 what does c =
    5·1 answer
  • 14 % of a value is £91<br> work out the original value<br> give your answer in pounds
    8·1 answer
  • Mrs. Harrold asked her reading class to make a graph illustrating the similarities and differences between the three stories. Wh
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!