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3 years ago

A group of 8 friends (5 girls and 3 boys) plans to watch a movie, but they have only 5 tickets. If they randomly decide who

Mathematics

1 answer:

nalin [4]3 years ago

8 0

Answer:

53.57%

Step-by-step explanation:

We have to calculate first the specific number of events that interest us, if at least 3 are girls, they mean that 2 are boys, therefore we must find the combinations of 3 girls of 5 and 2 boys of 3, and multiply that, so :

# of ways to succeed = 5C3 * 3C2 = 5! / (3! * (5-3)!) * 3! / (2! * (3-2)!)

= 10 * 3 = 30

That is, there are 30 favorable cases, now we must calculate the total number of options, which would be the combination of 5 people from the group of 8.

# of random groups of 5 = 8C5 = 8! / (5! * (8-5)!) = 56

That is to say, in total there are 56 ways, the probability would be the quotient of these two numbers like this:

P (3 girls and 2 boys) = 30/56 = 0.5357

Which means that the probability is 53.57%

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The length of a rectangular pool is 20 feet and the width is 15 feet. The

Ray Of Light [21]

Answer:

$255

Step-by-step explanation:

As, the area of the pool bottom = length x breath

= 20 x 15 = 300 square foot

So for painting

Per square foot = $0.85

So for 300 square foot = $0.85 x 300

= $255

5 0

3 years ago

Can someone please help. what is 2L+Z+N+H-Z=

Strike441 [17]

Yhgghhccvfcbfcgfcfcv

8 0

3 years ago

A certain pen has been designed so that true average writing lifetime under controlled conditions (involving the use of a writin

Morgarella [4.7K]

Answer:

(a) We reject our null hypothesis.

(b) We fail to reject our null hypothesis.

(c) We fail to reject our null hypothesis.

Step-by-step explanation:

We are given that a certain pen has been designed so that true average writing lifetime under controlled conditions (involving the use of a writing machine) is at least 10 hr.

A random sample of 18 pens is selected.

Let $\mu$ = true average writing lifetime under controlled conditions

So, Null Hypothesis, $H_0$ : $\mu \geq$ 10 hr {means that the true average writing lifetime under controlled conditions is at least 10 hr}

Alternate Hypothesis, $H_A$ : $\mu$ < 10 hr {means that the true average writing lifetime under controlled conditions is less than 10 hr}

The test statistics that is used here is one-sample t test statistics;

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

where, $\bar X$ = sample mean

s = sample standard deviation

n = sample size of pens = 18

n - 1 = degree of freedom = 18 -1 = 17

Now, the decision rule based on the critical value of t is given by;

If the value of test statistics is more than the critical value of t at 17 degree of freedom for left-tailed test, then we will not reject our null hypothesis as it will not fall in the rejection region.

If the value of test statistics is less than the critical value of t at 17 degree of freedom for left-tailed test, then we will reject our null hypothesis as it will fall in the rejection region.

(a) Here, test statistics, t = -2.4 and level of significance is 0.05.

Now, at 0.05 significance level, the t table gives critical value of -1.74 at 17 degree of freedom.

Here, clearly the value of test statistics is less than the critical value of t as -2.4 < -1.74, so we reject our null hypothesis.

(b) Here, test statistics, t = -1.83 and level of significance is 0.01.

Now, at 0.051 significance level, the t table gives critical value of -2.567 at 17 degree of freedom.

Here, clearly the value of test statistics is more than the critical value of t as -2.567 < -1.83, so we fail to reject our null hypothesis.

(c) Here, test statistics, t = 0.57 and level of significance is not given so we assume it to be 0.05.

Now, at 0.05 significance level, the t table gives critical value of -1.74 at 17 degree of freedom.

Here, clearly the value of test statistics is more than the critical value of t as -1.74 < 0.57, so we fail to reject our null hypothesis.

8 0

3 years ago

MATH HELP FIND THE EQUATION OF THE LINE

Dominik [7]

y=3/3x+-2

Step-by-step explanation:

it goes up 3 and over 3 so its 3/3 and it starts at -2

5 0

3 years ago

Read 2 more answers

Three cards are chosen from a standard deck of 52 playing cards with replacement what is the orobsbility every card will be a he

Ne4ueva [31]

1/4 x 1/4 x 1/4 = 1/64

There is a 1/64 chance that they will all be hearts.

7 0

4 years ago