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2 years ago

14

You and your 8 friends decide to draw straws for a prize. There are 8 long straws and 1 short straw. Describe how the theoretica

l probability of drawing the short straw changes as each friend picks a straw.

1 answer:

OleMash [197]2 years ago

5 0

To start off with, the probability to draw the short straw is 1/9 and each time someone picks the long straw the denominator (the 9) decreases by one which means that the odds of someone picking it get higher.

You might be interested in

Find the distance between the points (0,-8) and (3,2). Round your answer to the nearest hundredth.

Reil [10]

Answer:

10.44

Step-by-step explanation:

First plot each of the points on to a graph at their respective positions.

Following that create a 90° triangle out of the points. This will create a 3 by 10 triangle. (3 to 0 is 3) (-8 to 2 is a difference of 10)

You can then use the pythagorean theorem $a^{2} +b^{2} = c^{2}$ .

Insert the lengths of each of the sides that we got earlier which would be 3 and 10 into the equation. $3^{2} + 10^{2} = c^{2}$

Since we want to find the hypotenuse which is equal to c we work the equation to 9+100 = $c^{2}$ which in turn is 109 = $c^{2}$

Then take the square root of 109 to remove the square from the c to get c = 10.44

6 0

3 years ago

A doctor at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she

Nataly_w [17]

Answer:

The minimum sample size needed is $n = (\frac{1.96\sqrt{\sigma}}{4})^2$ . If n is a decimal number, it is rounded up to the next integer. $\sigma$ is the standard deviation of the population.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?

A sample of n is needed, and n is found when M = 4. So

$M = z\frac{\sigma}{\sqrt{n}}$

$4 = 1.96\frac{\sigma}{\sqrt{n}}$

$4\sqrt{n} = 1.96\sqrt{\sigma}$

$\sqrt{n} = \frac{1.96\sqrt{\sigma}}{4}$

$(\sqrt{n})^2 = (\frac{1.96\sqrt{\sigma}}{4})^2$

$n = (\frac{1.96\sqrt{\sigma}}{4})^2$

The minimum sample size needed is $n = (\frac{1.96\sqrt{\sigma}}{4})^2$ . If n is a decimal number, it is rounded up to the next integer. $\sigma$ is the standard deviation of the population.

4 0

2 years ago

A circle has center

Fed [463]

Note that the equation of the circle is

(x-h)² +(y-k)² =r²

where centre is (h,k)

the equation of the circle based on the information given

(x-3)² +(y-4)² =r²
and the point on the circle (3,-2)

substitute into the equation

(3-3)² +(-2-4)² =r²

r=6 or r=-6

since r is radius, we reject r=-6 since radius must be nonnegative.

the radius is 6

5 0

1 year ago

you currently have 24 credit hours and a 2.8 gpa you need a 3.0 gpa to get into the college. if you are taking a 16 credit hours

Juliette [100K]

Answer:

$\sum_{i=1}^n w_i *X_i = 2.8*24 = 67.2$

And for this case we want a gpa of 3.0 taking in count that in this semester he/ she is going to take 16 credits so then the new mean would be given by:

$\bar X_f = \frac{\sum_{i=1}^n w_i *X_i+w_f *X_f }{24+16} = 3.0$

And we can solve for $\sum_{i=1}^n w_f *X_f$ and solving we got:

$3.0 *(24+16) =\sum_{i=1}^n w_i *X_i +\sum_{i=1}^n w_f *X_f$

And from the previous result we got:

$3.0 *(24+16) =67.2 +\sum_{i=1}^n w_f *X_f$

And solving we got:

$\sum_{i=1}^n w_f *X_f =120 -67.2= 52.8$

And then we can find the mean with this formula:

$\bar X_2 = \frac{\sum_{i=1}^n w_f *X_f}{16}= \frac{52.8}{16}=16=3.3$

So then we need a 3.3 on this semester in order to get a cumulate gpa of 3.0

Step-by-step explanation:

For this case we know that the currently mean is 2.8 and is given by:

$\bar X = \frac{\sum_{i=1}^n w_i *X_i }{24} = 2.8$

Where $w_i$ represent the number of credits and $X_i$ the grade for each subject. From this case we can find the following sum:

$\sum_{i=1}^n w_i *X_i = 2.8*24 = 67.2$

And for this case we want a gpa of 3.0 taking in count that in this semester he/ she is going to take 16 credits so then the new mean would be given by:

$\bar X_f = \frac{\sum_{i=1}^n w_i *X_i+w_f *X_f }{24+16} = 3.0$

And we can solve for $\sum_{i=1}^n w_f *X_f$ and solving we got:

$3.0 *(24+16) =\sum_{i=1}^n w_i *X_i +\sum_{i=1}^n w_f *X_f$

And from the previous result we got:

$3.0 *(24+16) =67.2 +\sum_{i=1}^n w_f *X_f$

And solving we got:

$\sum_{i=1}^n w_f *X_f =120 -67.2= 52.8$

And then we can find the mean with this formula:

$\bar X_2 = \frac{\sum_{i=1}^n w_f *X_f}{16}= \frac{52.8}{16}=16=3.3$

So then we need a 3.3 on this semester in order to get a cumulate gpa of 3.0

6 0

2 years ago

Find the domain and range of the relation.<br> {(3,-2) (2,1) (-1,0) (1,3)}

svp [43]

The domain of the inverse of a relation is the same as the range of the original relation. In other words, the y-values of the relation are the x-values of the inverse.

5 0

2 years ago