4. If f(x) = 4x - 9, what is the equation for f1(x)?

16. A telemarketer makes six phone calls per hour and is able to make a sale on 30% of these contacts. During the next two hours

Reika [66]

Answer:

a) 23.11% probability of making exactly four sales.

b) 1.38% probability of making no sales.

c) 16.78% probability of making exactly two sales.

d) The mean number of sales in the two-hour period is 3.6.

Step-by-step explanation:

For each phone call, there are only two possible outcomes. Either a sale is made, or it is not. The probability of a sale being made in a call is independent from other calls. So we use the binomial probability distribution 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.

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

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.

A telemarketer makes six phone calls per hour and is able to make a sale on 30% of these contacts. During the next two hours, find:

Six calls per hour, 2 hours. So

$n = 2*6 = 12$

Sale on 30% of these calls, so $p = 0.3$

a. The probability of making exactly four sales.

This is P(X = 4).

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

$P(X = 4) = C_{12,4}.(0.3)^{4}.(0.7)^{8} = 0.2311$

23.11% probability of making exactly four sales.

b. The probability of making no sales.

This is P(X = 0).

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

$P(X = 0) = C_{12,0}.(0.3)^{0}.(0.7)^{12} = 0.0138$

1.38% probability of making no sales.

c. The probability of making exactly two sales.

This is P(X = 2).

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

$P(X = 2) = C_{12,2}.(0.3)^{2}.(0.7)^{10} = 0.1678$

16.78% probability of making exactly two sales.

d. The mean number of sales in the two-hour period.

The mean of the binomia distribution is

$E(X) = np$

So

$E(X) = 12*0.3 = 3.6$

The mean number of sales in the two-hour period is 3.6.

4 0

2 years ago

Write the value of 4 in 305,444

BigorU [14]

Divide 305444 by 4

305444 / 4
76361

so
76361 times 4 is equal to 76361

3 0

2 years ago

Read 2 more answers

A bookstore marks up the price of a book by 25% of the cost from the publisher. Therefore, the

lesya692 [45]

Answer:

(A)

P(60) = 78.98
When the bookstore spends $60 on a textbook, the student pays $78.98

Step-by-step explanation:

Given:

P(x) = 1.053(x+0.25x)

P(60) = 1.053(60+0.25*60)

=1.053(60+15)

=1.053(75)

P(60)=$78.98

Since x is the cost from the publisher, when the bookstore spends $60 on a textbook, the student pays $78.98.

The correct option is A.

3 0

3 years ago

Write an inequality for the graph A. x > -3 B. x < -3 c. x > -3 _

earnstyle [38]

Answer:

A. x > -3

Step-by-step explanation:

Well by looking at the graph we can tell that,

the line we can tell that the line goes to the right of of the number line,

Meaning x is greater than -3.

Thus,

x > -3.

Hope this helps :)

5 0

3 years ago

Finding Derivatives Implicity In Exercise, find dy/dx implicity. 4x3 + ln y2 + 2y = 2x

lisov135 [29]

Answer:

$\frac{dy}{dx}=\frac{y(1-6x^2)}{(1+y)}$

Step-by-step explanation:

Given function : 4x³ + ln(y²) + 2y = 2x

on differentiating both sides with respect to 'x', we get

$\frac{d(4x^3 + ln(y^2) + 2y)}{dx}= \frac{d(2x)}{dx}$

or

$12x^2+\frac{2}{y}(\frac{dy}{dx})+2(\frac{dy}{dx})=2$

or

$12x^2+(\frac{2}{y}+2)\frac{dy}{dx}=2$

or

$(\frac{2+2y}{y})\frac{dy}{dx}=2-12x^2$

or

$\frac{dy}{dx}=\frac{y(2-12x^2)}{2+2y}$

or

$\frac{dy}{dx}=\frac{2y(1-6x^2)}{2(1+y)}$

or

$\frac{dy}{dx}=\frac{y(1-6x^2)}{(1+y)}$

3 0

2 years ago