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Lorico [155]
2 years ago
7

You have a coin collection of nickels and dimes containing 63 coins. If you have

Mathematics
1 answer:
xxTIMURxx [149]2 years ago
6 0

Answer: 25 nickels

Step-by-step explanation:

EQUATIONS:

quantity: n + d = 63

value: 5n + 10d = 505

-------------------------

Divide thru the 2nd equation by 5 to get:

n + 2d = 101

----------------

Subtract that from the 1st equation:

-d = -38

d = 38 (# of dimes)

---------------

Substitute that into n+d=63 to solve for "n":

n + 38 = 63

n = 25 (# of nickels)

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A practice law exam has 100 questions, each with 5 possible choices. A student took the exam and received 13 out of 100.If the s
Cloud [144]

Answer:

z=\frac{13-20}{4}=-1.75

Assuming:

H0: \mu \geq 20

H1: \mu

p_v = P(Z

Step-by-step explanation:

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest (number of correct answers in the test), on this case we now that:

X \sim Binom(n=100, p=0.2)

The probability mass function for the Binomial distribution is given as:

P(X)=(nCx)(p)^x (1-p)^{n-x}

Where (nCx) means combinatory and it's given by this formula:

nCx=\frac{n!}{(n-x)! x!}

We need to check the conditions in order to use the normal approximation.

np=100*0.2=20 \geq 10

n(1-p)=20*(1-0.2)=16 \geq 10

So we see that we satisfy the conditions and then we can apply the approximation.

If we appply the approximation the new mean and standard deviation are:

E(X)=np=100*0.2=20

\sigma=\sqrt{np(1-p)}=\sqrt{100*0.2(1-0.2)}=4

So we can approximate the random variable X like this:

X\sim N(\mu =20, \sigma=4)

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".  The letter \phi(b) is used to denote the cumulative area for a b quantile on the normal standard distribution, or in other words: \phi(b)=P(z

The z score is given by this formula:

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

If we replace we got:

z=\frac{13-20}{4}=-1.75

Let's assume that we conduct the following test:

H0: \mu \geq 20

H1: \mu

We want to check is the score for the student is significantly less than the expected value using random guessing.

So on this case since we have the statistic we can calculate the p value on this way:

p_v = P(Z

5 0
3 years ago
Thrice the product of two and "Y".
love history [14]

Answer:

6Y

Step-by-step explanation:

We need to solve the statement ' Thrice the product of two and "Y" '.

Thrice means 3 times and product means multiply. It means we have to multiply 3,2 and Y.

Let the result is R. It can be calculated as follows :

R=3\times 2\times Y

We know that, 3×2 = 6

So,

R=6Y

Hence, Thrice the product of two and "Y" is 6Y.

6 0
3 years ago
Need help with number 43 and 45 and need to show the work
Alex787 [66]
43:
       Negative temperatures are basically the same as normal ones, although they go below zero, so they are still the same distance apart from zero, just on the left side of the number line.

      To find the answer find the difference between 30.5°C and 0 (which is 30.5).

      Next, find the difference between -122.2°C and zero (122.2)

       Finally, add 122.2 + 30.5 to find the total distances from the zero combined for the full distances apart from each other.

     (We add them because -122.2 to the left of zero, and 30.5 is on the right)

      You should get 152.7 as your answer.

45:
     I'm guessing since it is asking for the deepest point (-5315) from sea level (0), the answer is -5,315 feet

     *Remember 5,315 is negative because numbers below sea level are all negative*

     So the answer should be -5,315 feet deep. (I'm not sure how to show your work for that I'm guessing it is 0 - 5,315 at the slightest).

 *Hope this all helped :)*

5 0
2 years ago
(-2.04) (-0.04) What is the product of the expression above?​
aleksley [76]

Answer:

0.0816

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
The Surface Area of this cylinder rounded to the nearest square
kipiarov [429]

Answer:

1728

Step-by-step explanation:

2\pir h

2\pi(11) × 14

968

B=\pi r^{2}

B=\pi11^2 =121\pi

S=2\pirh + 2\pi r^{2}

S=968 +2 x 121

S=968 +242\pi= 1728

6 0
3 years ago
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