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4 years ago

Mr. Martin is giving a math test next period. The test, which is worth 100 points, has 29 problems. Each problem is

Mathematics

1 answer:

Vesnalui [34]4 years ago

7 0

Answer:

x + y = 29

5x + 2y = 100

Step-by-step explanation:

Has 29 problems

then

x + y = 29

x be the number of worth 5 points questions:

y be the number of worth 2 points questions

the total both worth is 100 points

then:

5x + 2y = 100

Answer:

x + y = 29 5x + 2y = 100

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The length of a rectangle is four times its width. If the area is 400 cm squared, find its perimeter

nadya68 [22]

If width of rectangle is a, then length is 4a and area = 4a2<span> which is given as 100 m</span>2<span>. So a=5. Perimeter of rectangle= a+a+4a+4a = 10a= 50m</span>

7 0

3 years ago

SHOW YOUR WORK

Kipish [7]

Answer: 70

plz give brainliest

Step-by-step explanation:

Solution:

Since

96 : 160 = 42 : X

Then we know

160/96 = X/42

Multiplying both sides by 42 cancels on the right

42 × (160/96) = (X/42) × 42

42 × (160/96) = X

Then solving for X

X = 42 × (160/96)

X = 70

Therefore

96 : 160 = 42 : 70

5 0

3 years ago

Read 2 more answers

Benjamin has 14.2 ounces of water for his plants. He has 10 plants and wants to give each plant the same amount of

frosja888 [35]

Answer:

1.42

Step-by-step explanation:

What you have to do is just divide 14.2 and 10 to get your answer.

4 0

3 years ago

Read 2 more answers

If X denotes the number of heads in n tosses of a coin, what is the standard deviation of the random variable X? Does this stand

vfiekz [6]

Answer:

$\sigma=\sqrt{np(1-p)}=\sqrt{n*0.5(1-0.5)}=\frac{\sqrt{n}}{2}$

As we can see the deviation is proportional to the value of n and if n increase then the deviation increases too. So then the deviation would be larger when n gets larger.

Step-by-step explanation:

Previous concepts

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".

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:

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

Solution to the problem

We can define the following random variable X ="Number of heads in n tosses of a coin".

We assume that the coin is fair and then $P(H)= 0.5$ for any trial so then we can model X with the following distribution:

$X \sim Bin (n, p=0.5)$

For this distribution the mean and variance are given by:

$E(X)=np=n*0.5=\frac{n}{2}$

$Var(X)= np(1-p) = n*0.5*(1-0.5) = 0.25 n = \frac{n}{4}$

And the deviation would be just the square root of the variance and we got:

$\sigma=\sqrt{np(1-p)}=\sqrt{n*0.5(1-0.5)}=\frac{\sqrt{n}}{2}$

Does this standard deviation get larger or smaller when n gets larger?

As we can see the deviation is proportional to the value of n and if n increase then the deviation increases too. So then the deviation would be larger when n gets larger.

3 0

3 years ago

The area of a trampoline is about 1.8 x 10' square inches. Write this number in standard form. Then represent the area of the tr

Anni [7]

<h3>Solution</h3>

1.8 × 10⁴

= 18 × 10³

= 180 × 10²

= 1800 × 10

= 18000

6 0

3 years ago