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Yuki888 [10]
2 years ago
11

A school class went on a field trip to see a magician perform there were 17 females 20 males in the class the magicians randomly

selected a volunteer from the audience in which had 52 females and 68 males given that the randomly selected audience member is a student from the class which equation can be used to find the probability p that the perdimos also a female?please help does anyone know the answer
Mathematics
1 answer:
Westkost [7]2 years ago
6 0

Answer:

P(B)= 17/20

Step-by-step explanation:

Hello!

The audience of the magic show is conformed by a total of 120 people, 52 of which are female and 68 are men.

Within the audience there is a school class of 37, of these students, 17 are female and 20 are male.

If a random member of the audience is selected as a volunteer:

Let "A" represent the event that "the selected volunteer is a student of the class"

And "B" the event that "the selected student is female"

You have to calculate the probability of the selected volunteer being female, given that it is a member of the school class.

Symbolically:

P(B|A)

Using the formula of conditional probabilities you can calculate it as:

P(B|A)= \frac{P(AnB)}{P(A)}

P(A∩B)= P(A)*P(B)= (\frac{37}{120} )*(\frac{17}{20} )= \frac{629}{2400}= 0.26

P(A)= \frac{37}{120} = 0.308

P(B|A)= \frac{P(AnB)}{P(A)}= \frac{629/2400}{37/120} = \frac{17}{20} = 0.85

As you can see the probability of the event "The volunteer is female given that it was a student of the school class" means that you already know the selected volunteer was a student and only needed to calculate the probability of that student being female.

P(B)= 17/20

I hope this helps!

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Answer:

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Step-by-step explanation:

point-slope form: m= \frac{y2-y1}{x2-x1}

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x1  y1   x2  y2

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

\frac{-6 - 5\\}{2 - 4} = m

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2 years ago
If a = 7 - 4√3, find the value of a + 1/a​
irga5000 [103]

Answer:

Step-by-step explanation:

To calculate a+1/a, we first need to calculate for a.

a = 7 - 4 * \sqrt[2]{3}

square root of 3 = 1.73

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a = 7 - 6.9

a = 0.1

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Now, in case 4 wasn't being multiplied with the square root of 3, and instead, it was four root of 3, I am gonna do the calculations again:

a = 7 - \sqrt[4]{3}

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Hope I Helped!

5 0
2 years ago
Again ... Commute times in the U.S. are heavily skewed to the right. We select a random sample of 500 people from the 2000 U.S.
VladimirAG [237]

Answer:

We conclude that the mean commute time in the U.S. is less than half an hour.

Step-by-step explanation:

We are given that a random sample of 500 people from the 2000 U.S. Census is selected who reported a non-zero commute time.

In this sample the mean commute time is 27.6 minutes with a standard deviation of 19.6 minutes.

Let \mu = <u><em>mean commute time in the U.S..</em></u>

So, Null Hypothesis, H_0 : \mu \geq 30 minutes      {means that the mean commute time in the U.S. is more than or equal to half an hour}

Alternate Hypothesis, H_A : \mu < 30 minutes     {means that the mean commute time in the U.S. is less than half an hour}

The test statistics that would be used here <u>One-sample t-test statistics</u> as we don't know about population standard deviation;

                           T.S. =  \frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }  ~ t_n_-_1

where, \bar X = sample mean commute time = 27.6 minutes

            s = sample standard deviation = 19.6 minutes

            n = sample of people from the 2000 U.S. Census = 500

So, <u><em>the test statistics</em></u>  =  \frac{27.6 -30}{\frac{19.6}{\sqrt{500} } }  ~ t_4_9_9

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The value of t test statistic is -2.738.

Since, in the question we are not given with the level of significance so we assume it to be 5%. <u>Now, at 5% significance level the t table gives critical values of -1.645 at 499 degree of freedom for left-tailed test.</u>

Since our test statistic is less than the critical value of t as -2.378 < -1.645, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which <u>we reject our null hypothesis.</u>

Therefore, we conclude that the mean commute time in the U.S. is less than half an hour.

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3 years ago
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KiRa [710]

Answer:

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C.I = -10 ± 6.494462

C. I = (-16.494 ; -3.506)

6 0
3 years ago
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