PLS HELP HURRY ILL MARK AS BRAINLESS WHATS THE ANSWER TO THESES 3 QUESTIONS

A bag contains 7 red marbles, 3 blue marbles and 5 green marbles. If three marbles

worty [1.4K]

Answer:

3.7%

Step-by-step explanation:

We know that from this situation, the probability of drawing a single green marble is 1/3. However, to find the probability of drawing 3 green marbles, we will need to do:

$P= \frac{1}{3}* \frac{1}{3}*\frac{1}{3}$

We get a probability of:

$P= \frac{1}{27}$

This converts to a percentage of:

$\frac{1}{27}= 0.037 \\ 0.037*100= 3.7%$

We get a percentage of 3.7%

8 0

3 years ago

Suppose a couple planned to have three children. Let X be the number of girls the couple has.

sesenic [268]

Answer:

a) {GGG, GGB, GBG, BGG, BBG, BGB, GBB, BBB}

b) {0,1,2,3}

c)

$P(X=2) = \dfrac{3}{8}$

d)

$P(\text{3 boys}) = \dfrac{1}{8}$

Step-by-step explanation:

We are given the following in the question:

Suppose a couple planned to have three children. Let X be the number of girls the couple has.

a) possible arrangements of girls and boys

Sample space:

{GGG, GGB, GBG, BGG, BBG, BGB, GBB, BBB}

b) sample space for X

X is the number of girls couple has. Thus, X can take the values 0, 1, 2 and 3 that is 0 girls, 1 girl, 2 girls and three girls from three children.

Sample space: {0,1,2,3}

c) probability that X=2

P(X=2)

That is we have to compute the probability that couple has exactly two girls.

$\text{Probability} = \displaystyle\frac{\text{Number of favourable outcomes}}{\text{Total number of outcomes}}$

Favorable outcome: {GGB, GBG, BGG}

$P(X=2) =\dfrac{3}{8}$

d) probability that the couple have three boys.

Favorable outcome: {BBB}

$P(BBB) = \dfrac{1}{8}$

8 0

3 years ago

9 packages of grape cost $24 how many packages of grapes can you buy for $8

Leto [7]

Ok. First you have to find the unit rate. Since you can buy 9 packages of grapes for $24, then you can get 1 grape package for $2.6667. If you have $8, you can buy 3 packages of grapes.

8 0

3 years ago

Read 2 more answers

Find the mean and range. 18 23 10 39 22 17 16 15

stepan [7]

Answer:

Hey there the answer to your question will be below

Step-by-step explanation:

Mean=20

Range=29

___________________________________________________

Range:

Xmas = 39 and Xmas = 10

39-10=29

____________________________________________________

Mean:

160/8 = 20

Hope that helps!

By: xBrainly

7 0

3 years ago

There were 800 math instructors at a mathematics convention. Forty instructors were randomly selected and given an IQ test. The

Leya [2.2K]

Answer:

95% confidence interval for the mean of the 800 instructors is [126.80 , 133.20].

Step-by-step explanation:

We are given that there were 800 math instructors at a mathematics convention.

Forty instructors were randomly selected and given an IQ test. The scores produced a mean of 130 with a standard deviation of 10.

Firstly, the pivotal quantity for 95% confidence interval for the population mean is given by;

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

where, $\bar X$ = sample mean score = 130

s = sample standard deviation = 10

n = sample of instructors = 40

$\mu$ = population mean of 800 instructors

Here for constructing 95% confidence interval we have used One-sample t test statistics as we know don't about population standard deviation.

So, 95% confidence interval for the population mean, $\mu$ is ;

P(-2.0225 < $t_3_9$ < 2.0225) = 0.95 {As the critical value of t at 39 degree of

freedom are -2.0225 & 2.0225 with P = 2.5%}

P(-2.0225 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.0225) = 0.95

P( $-2.0225 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.0225 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-2.0225 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.0225 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

95% confidence interval for $\mu$ = [ $\bar X-2.0225 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.0225 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $130-2.0225 \times {\frac{10}{\sqrt{40} } }$ , $130+2.0225 \times {\frac{10}{\sqrt{40} } }$ ]

= [126.80 , 133.20]

Therefore, 95% confidence interval for the mean of the 800 instructors is [126.80 , 133.20].

5 0

3 years ago

Read 2 more answers