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3 years ago

Is 23/40 a rational or irrational number? I'm not sure how to solve this one.

Mathematics

1 answer:

vfiekz [6]3 years ago

5 0

Answer:

23/40 is a rational number

Step-by-step explanation:

an irrational number cannot be written as a fraction - with a finite end. An irrational number would be a repeating decimal

You might be interested in

Simplify (2z^5)(12z^3)/4z^4

Sphinxa [80]

Answer:

$6z^{4}$

Step-by-step explanation:

Given in the question an expression,

$\frac{ (2z^5)(12z^3)}{4z^4}$

Step 1

Apply exponential "product rule"

$x^{m}x^{n}=x^{m+n}$

$\frac{ 12(2)z^5)(z^3)}{4z^4}$

$\frac{ (24)z^5)(z^3)}{4z^4}$

$\frac{ 24(z^{(5+3)})}{4z^4}$

$\frac{ 24(z^{8})}{4z^4}$

Step 2

Apply exponential " divide rule"

$\frac{x^{m}}{x^{n}}=x^{m-n}$

$\frac{24/4(z^{8})}{z^4}$

$\frac{6(z^{8})}{z^4}$

$\frac{6(z^{8-4})}{1}$

$6z^{4}$

5 0

3 years ago

At Pike Place Fish Market in Seattle, customers can purchase a variety of different types of seafood. One type of seafood sold a

allsm [11]

Answer:

$z=1.28$

And if we solve for a we got

$a=3.6 +1.28*0.8=4.624$

So the value of height that separates the bottom 90% of data from the top 10% is 4.624.

So then the best answer for this case would be:

C. 4.64

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:

$X \sim N(3.6,0.8)$

Where $\mu=3.6$ and $\sigma=0.8$

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.1$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.9 of the area on the left and 0.1 of the area on the right it's z=1.28. On this case P(Z<1.28)=0.9 and P(z>1.28)=0.1

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=1.28$

And if we solve for a we got

$a=3.6 +1.28*0.8=4.624$

So the value of height that separates the bottom 90% of data from the top 10% is 4.624.

So then the best answer for this case would be:

C. 4.64

8 0

3 years ago

Which values are the solutions of the compound inequality? Select all that apply.

evablogger [386]

Answer:

b, c, e

Step-by-step explanation:

First, just simplify the inequality.

-18 < 5x - 8 < 17

-10 < 5x < 25

-2 < x < 5

Answers that fit this inequality:

-1, 0, 3

3 0

3 years ago

According to a study, 50 % of adult smokers started smoking before 21 years old. 5 smokers 21 years old or older are randomly se

belka [17]

Answer:

a) The probability that at least 2 of them started smoking before 21 years of age is 0.1875 = 18.75%.

b) The probability that at most 4 of them started smoking before 21 years of age is 0.96875 = 96.875%.

c) The probability that exactly 3 of them started smoking before 21 years of age is 0.3125 = 31.25%.

Step-by-step explanation:

For each smoker, there are only two possible outcomes. Either they started smoking before 21 years old, or they did not. Smokers are independent, 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.

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