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1 year ago

A bag contains 3 red balls and 4 blue balls. 3 balls are selected at random. Find the probability of selecting 3 red balls.

Mathematics

1 answer:

QveST [7]1 year ago

3 0

Answer:

Step-by-step explanation:

red balls=3

blue balls=4

total balls=3+4=7

probability of selecting 3 red balls=3/7 ×2/6×1/5=1/35

selecting 1 red ball=3/7

after selecting there are two red balls and total balls are 6

so now P=2/6

and so on .

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Select all of the given points in the coordinate plane that lie on the graph of the linear equation 4x-y=3

galben [10]

Answer:

(x, y)=(3/4, 3)

Step-by-step explanation:

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2 years ago

The ratio of girls to boys in art class is 4:5 if there are 32 girls how many boys are there?

dem82 [27]

Answer:

there are 40 boys

Step-by-step explanation:

32/4=8 5*8=40

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2 years ago

The distribution of resistance for resistors of a certain type is known to be normal, with 10% of all resistors having a resista

baherus [9]

Answer:

The mean is 9.65 ohms and the standard deviation is 0.2742 ohms.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

10% of all resistors having a resistance exceeding 10.634 ohms

This means that when X = 10.634, Z has a pvalue of 1-0.1 = 0.9. So when X = 10.634, Z = 1.28.

$Z = \frac{X - \mu}{\sigma}$

$1.28 = \frac{10.634 - \mu}{\sigma}$

$10.634 - \mu = 1.28\sigma$

$\mu = 10.634 - 1.28\sigma$

5% having a resistance smaller than 9.7565 ohms.

This means that when X = 9.7565, Z has a pvalue of 0.05. So when X = 9.7565, Z = -1.96.

$Z = \frac{X - \mu}{\sigma}$

$-1.96 = \frac{9.7565 - \mu}{\sigma}$

$9.7565 - \mu = -1.96\sigma$

$\mu = 9.7565 + 1.96\sigma$

We also have that:

$\mu = 10.634 - 1.28\sigma$

$10.634 - 1.28\sigma = 9.7565 + 1.96\sigma$

$1.96\sigma + 1.28\sigma = 10.645 - 9.7565$

$3.24\sigma = 0.8885$

$\sigma = \frac{0.8885}{3.24}$

$\sigma = 0.2742$

The mean is

$\mu = 10.634 - 1.28\sigma = 10 - 1.28*0.2742 = 9.65$

The mean is 9.65 ohms and the standard deviation is 0.2742 ohms.

8 0

3 years ago

it cost $3.45 to buy 3/4 lb of chopped walnuts how much would it cost to purchase 7.2 lb of walnuts

andreev551 [17]

Answer:

Step-by-step explanation:

$33.12

you would divide 3.45 by 3 to get 1/4, which is 1.15, then multiply that by 4 to get the cost for one pound, which is 4.6. multiply 4.6 times 7.2 to get your answer of 33.12

5 0

2 years ago

A group of 31 friends gets together to pay a sport. First, people must be divided into teams. Each team has to have exactly 3 pl

Monica [59]

Answer:

10 teams (1 remainder)

Step-by-step explanation:

if each team has 3 players and there are 30 friends, divide that and youll end up with 10 teams. you will also have 1 remaining player

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2 years ago

A bag contains 3 red balls and 4 blue balls. 3 balls are selected at random. Find the probability of selecting 3 red balls. ​

A bag contains 3 red balls and 4 blue balls. 3 balls are selected at random. Find the probability of selecting 3 red balls.