Can someone help me with this pls

Assume that there is a 4% rate of disk drive failure in a year. a. If all your computer data is stored on a hard disk drive wit

kap26 [50]

Answer:

a) 99.84% probability that during a year, you can avoid catastrophe with at least one working drive

b) 99.999744% probability that during a year, you can avoid catastrophe with at least one working drive

Step-by-step explanation:

For each disk drive, there are only two possible outcomes. Either it works, or it does not. The disks are independent. So we use the binomial probability distribution 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.

4% rate of disk drive failure in a year.

This means that 96% work correctly, $p = 0.96$

a. If all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

This is $P(X \ geq 1)$ when $n = 2$

We know that either none of the disks work, or at least one does. The sum of the probabilities of these events is decimal 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ . So

$P(X \geq 1) = 1 - P(X = 0)$

In which

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

$P(X = 0) = C_{2,0}.(0.96)^{0}.(0.04)^{2} = 0.0016$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0016 = 0.9984$

99.84% probability that during a year, you can avoid catastrophe with at least one working drive

b. If copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

This is $P(X \ geq 1)$ when $n = 4$

We know that either none of the disks work, or at least one does. The sum of the probabilities of these events is decimal 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ . So

$P(X \geq 1) = 1 - P(X = 0)$

In which

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

$P(X = 0) = C_{4,0}.(0.96)^{0}.(0.04)^{4} = 0.00000256$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.00000256 = 0.99999744$

99.999744% probability that during a year, you can avoid catastrophe with at least one working drive

7 0

3 years ago

A volleyball reaches its maximum of 13 feet, 3 seconds after it is served. What quadratic formula could model the height of the

Katena32 [7]

Answer:

$H=-(t-3)^2+13$

Step-by-step explanation:

The path covered by the volleyball will be a downward parabola with the vertex being the highest point of the ball.

A general form of a downward parabola is given as:

$y=-a(x-h)^2+k$

Where $(h,k)$ is the vertex of the parabola and 'a' is a constant.

Now, let 'h' be the vertical height and 't' be the time taken.

So, the equation would be of the form:

$H=-a(t-h)^2+k$

Now, as per question:

h = 2 seconds, k = 13 feet.

$H=-a(t-3)^2+13$

Now, taking a = 1. So, the formula that can be used is:

$H=-(t-3)^2+13$

7 0

3 years ago

I really need the answers for 6-8

Yuliya22 [10]

Answer:

i know it breaks your heart move to a city in a broke down car

3 0

2 years ago

Use the accompanying table of standard scores and their percentiles under the normal distribution to find the approximate standa

olganol [36]

Answer:

option a

Step-by-step explanation:

markme brainliest

3 0

2 years ago

What is 1 5/8 divided by 5 1/7

weeeeeb [17]

Answer: 91/288

Step-by-step explanation: To divide mixed numbers, first write the mixed numbers as improper fractions.

We can do this by multiplying the denominator by the whole number and then adding the numerator. Then, we put our new numerator over our old denominator.

So here, we can write 1 and 5/8 as the improper fraction 13/8 and we can write 5 and 1/7 as the improper fraction 36/7.

So here, we have 13/8 ÷ 36/7.

Dividing by a fraction is the same as multiplying by the reciprocal of that fraction.

So here, 13/8 ÷ 36/7 is the same as 13/8 × 7/36.

So now we are simply multiplying fractions and we do this by multiplying across the numerators and multiply across the denominators.

$\frac{13}{8} x \frac{7}{36} = \frac{91}{288}$

So now we have 91/288 which is in lowest terms.

This means that 1 and 5/8 divided by 5 and 1/7 is 91/288.

7 0

3 years ago

Can someone help me with this pls​

Can someone help me with this pls