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xxTIMURxx [149]

3 years ago

8

Two hoses are filling a pool the first hose fills at a rate of x gallons per minute the second hose fills at a rate of 15 gallon

s per minute less than the first hose.

1 answer:

ohaa [14]3 years ago

7 0

The correct answer would be B!

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7 inches converted to feet

Zarrin [17]

<span>0.583333333 feet

If I helped, press "Thanks" button. It will make me happy</span>

5 0

3 years ago

If you start with 85 milligrams of Chromium 51, used to track red blood cells, which

zysi [14]

About 92 days are taken for 90 % of the material to <em>decay</em>.

The mass of radioisotopes ( $m$ ), measured in milligrams, decreases exponentially in time ( $t$ ), measured in days. The model that represents such decrease is described below:

$m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }$ (1)

Where:

$m_{o}$ - Initial mass, in milligrams.
$m(t)$ - Current mass, in milligrams.
$\tau$ - Time constant, in days.

In addition, the time constant is defined in terms of half-life ( $t_{1/2}$ ), in days:

$\tau = \frac{t_{1/2}}{\ln 2}$ (2)

If we know that $m_{o} = 85\,mg$ , $t_{1/2} = 27.7\,d$ and $m(t) = 8.5\,mg$ , then the time required for decaying is:

$\tau = \frac{t_{1/2}}{\ln 2}$

$\tau = \frac{27.7\,d}{\ln 2}$

$\tau \approx 39.963\,d$

$t = -\tau \cdot \ln \frac{m(t)}{m_{o}}$

$t = -(39.963\,d)\cdot \ln \frac{8.5\,mg}{85\,mg}$

$t\approx 92.018\,d$

About 92 days are taken for 90 % of the material to <em>decay</em>.

We kindly invite to check this question on half-life: brainly.com/question/24710827

8 0

2 years ago

Find the value of x. (3 points each)

AleksandrR [38]

Answer:

x+43 $1\frac{x}{y} 2$

Step-by-step explanation:

7 0

2 years ago

A survey said that 3 out of 5 students enrolled in higher education took at least one online course last fall. Explain your calc

marysya [2.9K]

Answer:

a) 60% probability that student took at least one online course

b) 40% probability that student did not take an online course

c) 12.96% probability that all 4 students selected took online courses.

Step-by-step explanation:

For each student, there are only two possible outcomes. Either they took at least one online course last fall, or they did not. The probability of a student taking an online course is independent of other students. 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.

3 out of 5 students enrolled in higher education took at least one online course last fall.

This means that $p = \frac{3}{5} = 0.6$

a) If you were to pick at random 1 student enrolled in higher education, what is the probability that student took at least one online course?

This is P(X = 1) when n = 1. So

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

$P(X = 1) = C_{1,1}.(0.6)^{1}.(0.4)^{0} = 0.6$

60% probability that student took at least one online course.

b) If you were to pick at random 1 student enrolled in higher education, what is the probability that student did not take an online course?

This is P(X = 0) when n = 1.

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

$P(X = 0) = C_{1,1}.(0.6)^{0}.(0.4)^{1} = 0.4$

40% probability that student did not take an online course

c) Now, consider the scenario that you are going to select random select 4 students enrolled in higher education. Find the probability that all 4 students selected took online courses

This is P(X = 4) when n = 4.

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

$P(X = 4) = C_{4,4}.(0.6)^{4}.(0.4)^{0} = 0.1296$

12.96% probability that all 4 students selected took online courses.

3 0

3 years ago

What is the slope of the line passing through the points (0, 4) and (−8, −1)?

Alchen [17]

Answer:

The answer is

$\frac{5}{8} \\$

Step-by-step explanation:

The slope of a line given two points can be found by using the formula

$m = \frac{ y_2 - y _ 1}{x_ 2 - x_ 1} \\$

where

(x1 , y1) and (x2 , y2) are the points

From the question the points are

(0, 4) and (−8, −1)

The slope is

$m = \frac{ - 1 - 4}{ - 8 - 0} = \frac{ - 5}{ - 8} = \frac{5}{8} \\$

We have the final answer as

$\frac{5}{8} \\$

Hope this helps you

4 0

3 years ago