A large disaster cleaning company estimates that 30 percent of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that it has contracted, find the probability that x (number of jobs finished on time) is within one standard deviation of the mean.

68.26% probability that the number of jobs finished on time is within 1 standard deviation of the mean.

Step-by-step explanation:

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

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

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.

Looking at a random sample of 8 jobs that it has contracted, find the probability that x (number of jobs finished on time) is within one standard deviation of the mean.

Within 1 standard deviation of the mean is from Z = -1 to Z = 1. So this probability is the pvalue of Z = 1 subtracted by the pvalue of Z = -1.

Z = 1 has a pvalue of 0.8413

Z = -1 has a pvalue of 0.1587

So there is a 0.8413 - 0.1587 = 0.6826 = 68.26% probability that the number of jobs finished on time is within 1 standard deviation of the mean.

Related Questions

(9x -2)(9x +2)

Step-by-step explanation:

Each of the terms in the difference is a perfect square, so the "perfect square trick" applies. The factors are the sum and difference of the square roots of the given terms.

• √(81x²) = 9x
• √4 = 2

81x² - 4 = (9x +2)(9x -2)

the second and third terms in the following fibonacci sequence are X and Y. write down algebraic expressions for the first, fourth and fifth terms

(Y-X), X, Y, (X+Y), (X+Y)+Y, ...

Step-by-step explanation:

FIBONACHI SEQUENCE IS A SPECIAL MATHEMATICAL SEQUENCE IN W/C YOU HAVE TO ADD THE LAST AND THE NEXT TERM TO GET THE FOLLOWING TERM, IF SO.. TO GET THE LAST TERM, JUST REDUCE THE 3RD TERM TO YOUR 2ND TERM

TO GET THE 4RTH AMD 5TH TERM, JUST ADD THE FLLOWING CONSECITIVE TERM AS SHOWN IN THE ANSWER

What does deleted account mean on a answered question

Answer: It basically means an account is deleted because they requested it, or a moderator deleted their account.

Step-by-step explanation:

If a user violates the guidelines, they'll get a warning, then a ban, and a permban. Account deletion is basically a permanent ban. If a user gets deleted, but there answers or questions didn't, they username is "Brainly User." You'll see this if a user got deleted.

on average the number of electric guitars sold in texas each year is $91,399, which is seven times the average number of guitars sold each year in Wyoming. How manu electric guitars, on average, are sold each year in Wyoming? Answers The average electric guitars sold each year in Wyoming is 13,057. What is Multiplication? Multiplication of two numbers is defined as the addition of one of the number repeatedly until the times of the other number. a × b means that a is added to itself b times or b is added to itself a times. Given that, on average the number of electric guitars sold in Texas each year is$91,399, which is seven times the average number of guitars sold each year in Wyoming.

Average number of guitars sold each year in Texas = 91,399

This number is seven times the average number of guitars sold each year in Wyoming.

Let x be the average number of guitars sold in Wyoming each year.

7x = 91,399

Dividing both sides of the equation by 7,

x = 91399 / 7

x = 13,057

Hence 13,057 electric guitars are sold each year in Wyoming.

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7x = 91399
x = 91399/7
x = 13057 <===

You have a piggy bank containing a total of 106 coins in dimes and quarters. If the piggy bank contains \$17.05, how many dimes are there in the piggy bank? There are how many dimes in the piggy bank.

63 dimes

Step-by-step explanation:

Set up a system of equations where d is the number of dimes and q is the number of quarters:

d + q = 106

0.1d + 0.25q = 17.05

Solve by elimination by multiplying the top equation by -0.25 to eliminate q:

-0.25d - 0.25q = -26.5

0.1d + 0.25q = 17.05

Add together and solve for d:

-0.15d = -9.45

d = 63

So, there were 63 dimes in the piggy bank

John has five apples and he gives two to his friend how many apples does John have left

3 apples

Step-by-step explanation:

Total amount of apple John has = 5 apples

Amount given out to his friend = 2 apples

Number of apples Joh have left = Total amount of apple - Amount given out

Number of apples Joh have left = 5 apples - 2 apples

Number of apples Joh have left = 3 apples

Hence John has 3 apples left