Simplify this correctly and get a lot of points! ;) ;) ;) 9x- 7i

Consider the probability that greater than 26 out of 124 software users will call technical support. Assume the probability that

Mekhanik [1.2K]

Answer:

Since $n(1-p) = 3.72 < 10$ , the normal curve cannot be used as an approximation to the binomial probability.

100% probability that greater than 26 out of 124 software users will call technical support.

Step-by-step explanation:

Test if the normal curve can be used as an approximation to the binomial probability by verifying the necessary conditions.

It is needed that:

$np \geq 10$ and $n(1-p) \geq 10$

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.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

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

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

Out of 124 software users

This means that $n = 124$

Assume the probability that a given software user will call technical support is 97%.

This means that $p = 0.97$

Conditions:

$np = 124*0.97 = 120.28 \geq 10$

$n(1-p) = 124*0.03 = 3.72 < 10$

Since $n(1-p) = 3.72 < 10$ , the normal curve cannot be used as an approximation to the binomial probability.

Consider the probability that greater than 26 out of 124 software users will call technical support.

The lowest possible probability of those is 27, so, if it is 0, since it is considerably below the mean, 100% probability of being greater. We have that:

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

$P(X = 27) = C_{124,27}.(0.97)^{27}.(0.03)^{97} = 0$

1 - 0 = 1

100% probability that greater than 26 out of 124 software users will call technical support.

3 0

3 years ago

Find the difference. -7-(-5)

Dvinal [7]

Answer:

Remember: minus a minus is a plus:

=11

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Pls help im very desperate i'll defenitely give brainliest

bagirrra123 [75]

Answer:

-25

Step-by-step explanation:

You can take 10÷-⅖=-25

7 0

2 years ago

Read 2 more answers

At the park there is a pool shaped like a circle. A ring-shaped path goes around the pool. Its inner diameter is 22yd and its ou

jeka94

First, we need to think about what we're actually solving for: the area of the path. To find this, we can find the area of the whole thing, minus the area of the pool.

The diagram would look something like the picture I attached. We know that to find the area of a circle, you do πr^2. The radius is half of the diameter, so halve the diameters:

22/2 = 11 yards
32/2 = 16 yards

Then solve for the area of both circles.
π $11^{2}$ $= 121$ π ≈ 380.13 (area of the pool)
π $16^{2}$ $= 256$ π ≈ 804.25 (area of the whole thing)

Next, subtract the area of the pool from the area of the whole thing to find the area of the walkway:
$804.25 - 380.13 = 424.12$ (area of the walkway)

Finally, divide the area of the walkway by 6 to see how many gallons of paint you'll need:

424.12 ÷ 6 ≈ 70.69

So you'll need 71 gallons of paint!

Hope I helped and let me know if you have any questions :)