1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Salsk061 [2.6K]
3 years ago
8

Assume that there is a 8​% rate of disk drive failure in a year. a. If all your computer data is stored on a hard disk drive wit

h 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?
Mathematics
1 answer:
romanna [79]3 years ago
8 0

Answer:

0.9936 = 99.36% probability that during a​ year, you can avoid catastrophe with at least one working​ drive

Step-by-step explanation:

For each disk, there are only two possible outcomes. Either it works, or it does not. The probability of a disk working is independent of any other disk, which 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.

Assume that there is a 8​% rate of disk drive failure in a year.

So 100 - 8 = 92% probability of working, which means that p = 0.92

Two disks are used:

This means that n = 2

What is the probability that during a​ year, you can avoid catastrophe with at least one working​ drive?

This is:

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}.(0.92)^{0}.(0.08)^{2} = 0.0064

P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0064 = 0.9936

0.9936 = 99.36% probability that during a​ year, you can avoid catastrophe with at least one working​ drive

You might be interested in
Find the midpoint of a and b when a has coordinates (-5,3) and b has coordinates (3,-1)
azamat
To find the x coordinate of the midpoint, add the x coordinates and divide by 2
(-5+3)/2 = -2/2 = -1
To find the y coordinate of the midpoint, add the y coordinates and divide by 2
(3+-1)/2 = 2/2 = 1
(-1,1)
6 0
2 years ago
Read 2 more answers
Based on historical data, your manager believes that 41% of the company's orders come from first-time customers. A random sample
TEA [102]

Answer:

The probability that the sample proportion is between 0.35 and 0.5 is 0.7895

Step-by-step explanation:

To calculate the probability that the sample proportion is between 0.35 and 0.5 we need to know the z-scores of the sample proportions 0.35 and 0.5.

z-score of the sample proportion is calculated as

z=\frac{p(s)-p}{\sqrt{\frac{p*(1-p)}{N} } } where

  • p(s) is the sample proportion of first time customers
  • p is the proportion of first time customers based on historical data
  • N is the sample size

For the sample proportion 0.35:

z(0.35)=\frac{0,35-0.41}{\sqrt{\frac{0.41*0.59}{72} } } ≈ -1.035

For the sample proportion 0.5:

z(0.5)=\frac{0,5-0.41}{\sqrt{\frac{0.41*0.59}{72} } } ≈ 1.553

The probabilities for z of being smaller than these z-scores are:

P(z<z(0.35))= 0.1503

P(z<z(0.5))= 0.9398

Then the probability that the sample proportion is between 0.35 and 0.5 is

P(z(0.35)<z<z(0.5))= 0.9398 - 0.1503 =0.7895

6 0
3 years ago
Equation of a circle whose center is at (4,0) and radius is length 2/3
Masteriza [31]
We need (x-h)^2 + (y-k)^2 = r^2

h = 4, k = 0 and r = 2/3

Take it from here.
5 0
3 years ago
A two-digit number becomes 5/6 of the reversed number obtained when the digits are interchanged. The difference between the digi
stealth61 [152]
<h3>Answer:   54</h3>

==============================================

Work Shown:

T = tens digit

U = units digit (aka ones digit)

A number like 27 is really 20+7 = 2*10 + 7*1 = 10*2 + 1*7. We have 2 in the tens digit and 7 in the units digit. So 27 can be written in the form 10T + U where T = 2 and U = 7. Reversing the digits gives 72, so T = 7 and U = 2 now. Clearly the difference between the digits 7 and 2 is not 1, so 27 or 72 is not the answer (as it's just an example).

-----------------------

Let T be larger than U. This doesn't work if T = U.

Because T is larger, saying "The difference between the digits is 1" means T - U = 1. We can isolate T to get T = U+1. We'll use this later.

-----------------------

If T > U, then the original number 10T+U reverses to the new number 10U+T and it becomes smaller. We are told that it becomes 5/6 of what it used to be.

So,

new number = (5/6)*(old number)

10U + T = (5/6)(10T + U)

6(10U + T) = 5(10T + U)

60U + 6T = 50T + 5U

60U + 6(U+1) = 50(U+1) + 5U ... plug in T = U+1

60U + 6U + 6 = 50U + 50 + 5U

66U + 6 = 55U + 50

66U - 55U = 50-6

11U = 44

U = 44/11

U = 4 is the units digit of the original number

T = U+1

T = 4+1

T = 5 is the tens digit of the original number

The original number is therefore 10T + U = 10*5+4 = 54.

We see the difference in their digits is T-U = 5-4 = 1

The reverse of 54 is 45. The number 45 is 5/6 of 54

45 = (5/6)*54

7 0
3 years ago
Given the data presented in the bar graph, which age group represents 25% of the people at the family reunion? A) 10−19 B) 20−29
Dmitriy789 [7]

Answer:

B

Step-by-step explanation:

First you find the amount of people at the reunion which was 80. Then you find 25% of 80. 25% of 80 is 20. The only age group with 20 people is the 20-29 year olds.

4 0
2 years ago
Read 2 more answers
Other questions:
  • The result of multiplying two or more numbers is a____
    13·1 answer
  • Can some one please help me thank you ☺️
    8·1 answer
  • Lydia uses 8.9 pints of blue paint and white paint to paint her bedroom walls. 4 5 of this amount is blue paint, and the rest is
    15·1 answer
  • Caley builds a rectangular prism using 18 cubes that each measure 1 centimeter on each side. What could be the dimensions of her
    8·2 answers
  • Sheila bought burgers and fries for her children and some friends. the burgers cost $2.05 each and the fries are $.85 each. she
    7·1 answer
  • 170 is one tenth of 17 true or false
    9·2 answers
  • A cookie recipe calls for 2 eggs and 3 cups of flour. Nisha plans to increase the recipe
    5·2 answers
  • help pleaseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
    9·2 answers
  • A prism has a volume of 225 cubic meters.
    10·1 answer
  • there were 936,795 bankruptcy filings in 2018. If there were 310,061 chapter 13 filings, what percent were not chapter 13
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!