Someone please help me i don’t know how to do this

A box contains 3 green marbles, 5 blue marbles, and 7 red marbles. Three marbles are selected at random from the box, one at a t

USPshnik [31]

Answer:

The probability is $P(K) = \frac{ 28 }{195}$

Step-by-step explanation:

From the question we are told that

The number of green marbles is $n_g = 3$

The number of red marbles is $n_b = 5$

The number of red marbles is $n_r = 7$

Generally the total number of marbles is mathematically represented as

$n_t = n_r + n_g + n_ b$

$n_t = 7 + 3 + 5$

$n_t = 5$

Generally total number of marbles that are not red is

$n_k = n_g + n_ b$

=> $n_k = 3 + 5$

=> $n_k = 8$

The probability of the first ball not being red is mathematically represented as

$P(r') = \frac{n_k}{n_t}$

=> $P(r') = \frac{ 8}{15}$

The probability of the second ball not being red is mathematically represented as

$P(r'') = \frac{n_k - 1}{n_t -1}$

=> $P(r'') = \frac{ 8 -1 }{15-1}$ (the subtraction is because the marbles where selected without replacement )

=> $P(r'') = \frac{ 7 }{14}$

The probability that the first two balls is not red is mathematically represented as

$P(R) = P(r') * P(r'')$

=> $P(R) = \frac{ 8}{15} * \frac{ 7 }{14}$

=> $P(R) = \frac{ 8 }{30}$

The probability of the third ball being red is mathematically represented as

$P(r) = \frac{n_r}{ n_t -2}$ (the subtraction is because the marbles where selected without replacement )

$P(r) = \frac{7}{ 15 -2}$

=> $P(r) = \frac{7}{ 13}$

Generally the probability of the first two marble not being red and the third marble being red is mathematically represented as

$P(K) = P(R) * P(r)$

$P(K) = \frac{ 8 }{30} * \frac{7}{ 13}$

=> $P(K) = \frac{ 28 }{195}$

6 0

2 years ago

Teresa counted the number of tomatoes in 9 baskets at a vegetable stand. The list shows the data. 11, 12, 8, 12, 8, 8, 11, 11, 9

barxatty [35]

Mean is 4
Median is 11

4 0

2 years ago

What value has a z-score of -0.67, if the mean is 18 and the standard deviation is 1.68?

uranmaximum [27]

The data point is 1.6 standard deviations above the mean.
Step-by-step explanation:
Z-score
It is the number of standard deviations from the mean that a data point is. It's a measure of how many standard deviations below or above the population mean a raw score is.
A Z-score is also known as a standard score and it can be placed on a normal distribution curve.
As in this case the Z-score is +1.6, so it means the data point is 1.6 standard deviations above the mean. Hope this helps I am kinda knew to this so I hope I helped you

7 0

2 years ago

A clipboard cost $2.23.It cost $0.58 more than a notebook.Lisa bought two clipboards and one notebook.She paid with a ten dollar

Katen [24]

First you'd subtract .58 from 2.23 to get the price of the notebook.

2.23 - .58 = 1.65

(2.23×2)+1.65= 6.11

Now subtract 6.11 from ten to figure out the change amount.

10 - 6.11 = 3.89

6 0

2 years ago

Read 3 more answers

Divisor of number <br>6?

mash [69]

Answer:

1 2 3 6

Step-by-step explanation:

1x6=6

2x3=6

3x2=6

6x1=6

6 0

2 years ago