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2 years ago

Do brainly users want private messaging

Mathematics

2 answers:

In-s [12.5K]2 years ago

4 0

Answer:

yea i do

Step-by-step explanation:

WITCHER [35]2 years ago

3 0

Answer:

No because they say we all need to talk as a community

Step-by-step explanation:

You might be interested in

A factory makes car batteries. The probability that a battery is defective is 1/14. If 400 batteries are tested, about how many

Rufina [12.5K]

Answer:

28.6, that is, about 29 are expected to be defective

Step-by-step explanation:

For each battery, there are only two possible outcomes. Either it is defective, or it is not. The probability of a battery being defective is independent of other betteries. So the binomial probability distribution is used to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The expected value of the binomial distribution is:

$E(X) = np$

The probability that a battery is defective is 1/14.

This means that $p = \frac{1}{14}$

400 batteries.

This means that $n = 400$

How many are expected to be defective?

$E(X) = np = 400*\frac{1}{14} = 28.6$

28.6, that is, about 29 are expected to be defective

3 0

3 years ago

Help will give Brainliest .!!!!

elena55 [62]

Answer:

these are the answers

Step-by-step explanation:

sorry it looks a little blurry

6 0

2 years ago

The speed of light is 3 x 108 m/s. If its frequency is 4.11 x 104 Hz, what is its wavelength?

QveST [7]

Answer:

Wave length = speed / frequency

Wave length = 3x10^8 / 4.11x10^4

Wave length = 7.299x10^3nm

Step-by-step explanation:

5 0

3 years ago

Aubrey invested $61,000 in an account paying an interest rate of 1.9% compounded continuously. Assuming no deposits or withdrawa

Hitman42 [59]

Answer: 9.9 years.

Step-by-step explanation:

If interest is compounded continuously, then formula to compute final amount A = $Pe^{rt}$ , where P =initial amount, r= rate of interest , t=time.

Given: P= $61,000, r= 1.9% =0.019 , A = $ 73600

Substitute all values in formula

$73600=61000e^{0.019t}\\\\\Rightarrow\ \dfrac{73600}{61000}=e^{0.019t}\\\\\Rightarrow\ 1.20655738=e^{0.019t}$

Taking natural log on both sides

$\ln (1.20655738)=0.019t\\\\\\ 0.18777116=0.019t\\\\\\ t=\dfrac{0.18777116}{0.019}\\\\\\ t=9.88269263\approx9.9\ \text{years}$

Hence, the required time = 9.9 years.

4 0

2 years ago

According to a 2018 survey by Bankrate, 20% of adults in the United States save nothing for retirement (CNBC website). Suppose t

nalin [4]

Answer:

0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement

Step-by-step explanation:

For each adult, there are only two possible outcomes. Either they save nothing for retirement, or they save something. The probability of an adult saving nothing for retirement is independent of any other adult. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

20% of adults in the United States save nothing for retirement (CNBC website).

This means that $p = 0.2$

Suppose that sixteen adults in the United States are selected randomly.

This means that $n = 16$

What is the probability that three or less of the selected adults have saved nothing for retirement?

This is:

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{16,0}.(0.2)^{0}.(0.8)^{16} = 0.0281$

$P(X = 1) = C_{16,1}.(0.2)^{1}.(0.8)^{15} = 0.1126$

$P(X = 2) = C_{16,2}.(0.2)^{2}.(0.8)^{14} = 0.2111$

$P(X = 3) = C_{16,3}.(0.2)^{3}.(0.8)^{13} = 0.2463$

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0281 + 0.1126 + 0.2111 + 0.2463 = 0.5981$

0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement

4 0

2 years ago