Use the method of substitution to solve this: 9x+4y=9/2 and y=2x-1

student randomly receive 1 of 4 versions(A, B, C, D) of a math test. What is the probability that at least 3 of the 5 student te

alexdok [17]

Answer:

1.2%

Step-by-step explanation:

We are given that the students receive different versions of the math namely A, B, C and D.

So, the probability that a student receives version A = $\frac{1}{4}$ .

Thus, the probability that the student does not receive version A = $1-\frac{1}{4}$ = $\frac{3}{4}$ .

So, the possibilities that at-least 3 out of 5 students receive version A are,

1) 3 receives version A and 2 does not receive version A

2) 4 receives version A and 1 does not receive version A

3) All 5 students receive version A

Then the probability that at-least 3 out of 5 students receive version A is given by,

$\frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}\times \frac{3}{4}\times \frac{3}{4}$ + $\frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}\times \frac{3}{4}$ + $\frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}\times \frac{1}{4}$

= $(\frac{1}{4})^3\times (\frac{3}{4})^2+(\frac{1}{4})^4\times (\frac{3}{4})+(\frac{1}{4})^5$

= $(\frac{1}{4})^3\times (\frac{3}{4})[\frac{3}{4}+\frac{1}{4}+(\frac{1}{4})^2]$

= $(\frac{3}{4^4})[1+\frac{1}{16}]$

= $(\frac{3}{256})[\frac{17}{16}]$

= 0.01171875 × 1.0625

= 0.01245

Thus, the probability that at least 3 out of 5 students receive version A is 0.0124

So, in percent the probability is 0.0124 × 100 = 1.24%

To the nearest tenth, the required probability is 1.2%.

4 0

3 years ago

This recipe makes 7 portions of chocolate mousse.

Artist 52 [7]

Answer

She would have to use 2700g chocolate, 150g eggs, 300ml lemon juice and 750 g of sugar.. to make 21 potions

_____________________________

5 0

3 years ago

theo made sails for a model boat.He cut along the diagonal of a rectangular piece of cloth to make two sails as shown below.What

schepotkina [342]

Given:

A rectangular piece of cloth (dimensions):

L = length of the rectangle
W = width of the rectangle

The area of the rectangle is:

A = L x W

If the cloth is cut along the diagonal, the area of one sail will be half the area of the rectangle:

A (one sail) = 1/2 (L x W) <span />

5 0

3 years ago

In a recent telephone survey, 5,000 randomly selected teenagers were asked to cite their primary social network sites. Six of 10

aleksklad [387]

Answer:

b. There is a 95% chance that the true proportion of teenagers who use Mybook as their primary social network site is in the interval (0.2964, 0.9036).

Step-by-step explanation:

Hello!

In general, a 95% confidence interval for the population proportion can be interpreted as: There is a 95% chance (or confidence) that the interval will contain the true value of the proportion.

(Remember the confidence level of 95% means that if you were to make 100 intervals for the population proportion, 95 of them will contain its true value)

The estimated parameter is the population proportion of teenagers that use Mybook as their primary social network site.

With this in mind then you can say that there is a 95% probability that the interval (0.2964, 0.9036) will contain the true value of the proportion of teenagers that use Mybook as their primary social network site.

The correct answer is: b

I hope this helps!

8 0

3 years ago

Alexandra paid \$7$7dollar sign, 7 to park her car for 333 hours at the parking garage. The garage charges an hourly parking rat

NeX [460]

Assuming that the fee is purely based on duration, the equation would look like this:
c= a*p
where c= cost, a= rates per hour, p= hours of parking

Alexandra pays 7$ for 3 hours parking. So, a would be:
c= a*p
7$= a * 3 hr
a= 7$/3hr

Then the final equation would be:
c= (7/3) *p

8 0

3 years ago

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