How would you solve 7y = 8y + 2.

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

1 point) during a winter season at one ski resort, there are two roads from area a to area b and two roads from area b to area

miss Akunina [59]

Probability that both roads from a to b are blocked is the product of the individual probabilities, i.e.
P(~ab)=0.25*0.25=0.0625
Similarly
P(~bc)=0.25*0.25=0.0625
Probability that EITHER one or both of ab and bc are blocked is the sum of the probabilities:
P(~ab ∪ ~bc)=0.0625+0.0625=0.125
(recall that one cannot travel from a to c if either ab or bc is blocked.)

Therefore the probability that there exists an open route from a to c
= P(ac) = 1-P(~ab ∪ ~bc)
= 1 - 0.125
=0.875

5 0

3 years ago

An isosceles triangle has a vertical angle of 108 and a base 20 cm long. Solve for the base angles in calculated altitude.

xeze [42]

Answer:

The base angles are 36° each

Step-by-step explanation:

An isosceles triangle is a triangle that has two of its sides and base angles to be equal.

If an isosceles triangle has a vertical angle of 108°, then the base angles will share the remaining angle in the triangle equally.

Since the sum of angles in a triangle is 180°

The remaining angle in the triangle = 180°-108°

= 72°

Since the base angles are equal, this remaining two angles will share angle 72° equally.

The base angles = 72°/2

The base angles = 36°

This shows that the base angles are 36° each.

8 0

3 years ago

Is 46 greater or less than -79

Alona [7]

Answer:

46 is greater than -79

6 0

3 years ago

Read 2 more answers

The universal ga law PV=net describes the relationship among the pressure volume and temperature of a gas.

miskamm [114]

Answer:

R ≈ 8.31

Step-by-step explanation:

Filling in the given values ...

... pV = nRT

... 2·4.155 = 1·R·1

... 8.31 = R

7 0

3 years ago