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3 years ago

5

Is the following number rational or irrational?

1 answer:

mariarad [96]3 years ago

7 0

Answer:

it is rational cause it can be turned into a fraction 0.7= 7/10

You might be interested in

. Find the inverse of the function below on the given interval and write it in the form yequalsf Superscript negative 1 Baseline

Elena L [17]

Answer:

The inverse of the function is $f^{-1}(x)=\frac{x-5}{3}$ .

Step-by-step explanation:

The function provided is:

$f (x)=3x+5$

Let $f(x)=y$ .

Then the value of <em>x</em> is:

$y=3x+5\\\\3x=y-5\\\\x=\frac{y-5}{3}$

For the inverse of the function, $x\rightarrow y$ .

⇒ $f^{-1}(x)=\frac{x-5}{3}$

Compute the value of $f[f^{-1}(x)]$ as follows:

$f[f^{-1}(x)]=f[\frac{x-5}{3}]$

$=3[\frac{x-5}{3}]+5\\\\=x-5+5\\\\=x$

Hence proved that $f[f^{-1}(x)]=x$ .

Compute the value of $f^{-1}[f(x)]$ as follows:

$f^{-1}[f(x)]=f^{-1}[3x+5]$

$=\frac{(3x+5)-5}{3}\\\\=\frac{3x+5-5}{3}\\\\=x$

Hence proved that $f^{-1}[f(x)]=x$ .

8 0

3 years ago

What is the domain of the function

kati45 [8]

Answer:

it will be the first one

Step-by-step explanation:

3 0

3 years ago

Describe how to write an equivalent ratio for 9/27 without using a multiplication table

Ket [755]

We can divide. 9 Goes into 27 3 times so:

9/27 = 1/3

Hope this helped!

4 0

3 years ago

A. What is the slope of the line passing through the points (2,3) and (2,-3)?

OlgaM077 [116]

Answer:

The slope is the change in Y over the change in X:

Slope = (-3 - 3) / (2 -2) = 0/0

Since the slope contains a division of 0, it is undefined, therefore the answer would be neither.

3 0

4 years ago

Past records indicate that the probability of online retail orders

Tcecarenko [31]

Answer:

a) Mean = 1.6, standard deviation = 1.21

b) 18.87% probability that zero online retail orders will turn out to be fraudulent.

c) 32.82% probability that one online retail order will turn out to be fraudulent.

d) 48.31% probability that two or more online retail orders will turn out to be fraudulent.

Step-by-step explanation:

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.

The mean of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

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

In this problem, we have that:

$p = 0.08, n = 20$

a. What are the mean and standard deviation of the number of online retail orders that turn out to be fraudulent?

Mean

$E(X) = np = 20*0.08 = 1.6$

Standard deviation

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{20*0.08*0.92} = 1.21$

b. What is the probability that zero online retail orders will turn out to be fraudulent?

This is P(X = 0).

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

$P(X = 0) = C_{20,0}.(0.08)^{0}.(0.92)^{20} = 0.1887$

18.87% probability that zero online retail orders will turn out to be fraudulent.

c. What is the probability that one online retail order will turn out to be fraudulent?

This is P(X = 1).

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

$P(X = 1) = C_{20,1}.(0.08)^{1}.(0.92)^{19} = 0.3282$

32.82% probability that one online retail order will turn out to be fraudulent.

d. What is the probability that two or more online retail orders will turn out to be fraudulent?

Either one or less is fraudulent, or two or more are. The sum of the probabilities of these events is decimal 1. So

$P(X \leq 1) + P(X \geq 2) = 1$

We want $P(X \geq 2)$

So

$P(X \geq 2) = 1 - P(X \leq 1)$

In which

$P(X \leq 1) = P(X = 0) + P(X = 1)$

From itens b and c

$P(X \leq 1) = 0.1887 + 0.3282 = 0.5169$

$P(X \geq 2) = 1 - P(X \leq 1) = 1 - 0.5169 = 0.4831$

48.31% probability that two or more online retail orders will turn out to be fraudulent.

4 0

4 years ago