may you help me with this question?

Answer:

The half-life of this radioactive substance is of 8.6 months.

Step-by-step explanation:

Exponential decay of an amount:

The equation that models an amount after t units of time, subject to exponential decay, is given by:

[tex]A(t) = A(0)(1-r)^t[/tex]

In which A(0) is the initial amount and r is the decay rate, as a decimal.

A radioactive substance decays to 30% of its original mass in 15 months.

This means that [tex]A(15) = 0.3A(0)[/tex]. We use this to find 1 - r.

[tex]A(t) = A(0)(1-r)^t[/tex]

[tex]0.3A(0) = A(0)(1-r)^{15}[/tex]

[tex](1-r)^{15} = 0.3[/tex]

[tex]\sqrt[15]{(1-r)^{15}} = \sqrt[15]{0.3}[/tex]

[tex]1 - r = (0.3)^{\frac{1}{15}}[/tex]

[tex]1 - r = 0.9229[/tex]

So

[tex]A(t) = A(0)(0.9229)^t[/tex]

Determine the half-life of this radioactive substance to the nearest tenth.

This is t for which A(t) = 0.5A(0). So

[tex]A(t) = A(0)(0.9229)^t[/tex]

[tex]0.5A(0) = A(0)(0.9229)^t[/tex]

[tex](0.9229)^t = 0.5[/tex]

[tex]\log{(0.9229)^t} = \log{0.5}[/tex]

[tex]t\log{0.9229} = \log{0.5}[/tex]

[tex]t = \frac{\log{0.5}}{\log{0.9229}}[/tex]

[tex]t = 8.6[/tex]

The half-life of this radioactive substance is of 8.6 months.

Answer:

Length of Line AC = 26 units

Step-by-step explanation:

Given:

Line AC = [3x + 1] + 8

Line BC = [x - 2] + 2

Find:

Length of Line AC

Computation:

Line AB ║ Line L

So,

Using Mid-Point theorem;

[3x + 1] / 8 = [x - 2] / 2

2[3x + 1] = 8[x - 2]

6x + 2 = 8x - 16

8x - 6x = 16 + 2

2x = 18

x = 9

So,

Line AC = [3x + 1] + 8

Line AC = [3(9) + 1] + 8

Line AC = [27 + 1] + 8

Line AC = 28 + 8

Length of Line AC = 26 units

Answer:

Step-by-step explanation:

11 no

46+4x=90 degree(being perpendicular)

4x=90-46

x=44/4

x=11

12 no

They are complementary angles

6 no

angle B+27=180 degree(being straight line)

angle B=180-27

angle B=153

10 no

angle 38 +angle DFE=180 degree(being supplementary)

angle DFE=180-38

angle DFE=142 degree

5 no

They are vertically opposite angles.

7 no

angle AGF and angle CGD (because they have common arm and vertex)

Answer:

Solution given:

11.4x+46=90[being right angle]

4x=90-46

x=44/4

x=11

12.

Complementary angles

5.

vertical

6.

<ABD+27=180°[linear pair]

<ABD=180-27

<ABD=153° degree

10.

<DFE+38=180[being supplementary]

<DFE=180-38

<DFE=142 degrees.

7.

angle DGE and angle DGC

8.

<AGB and <AGE

Answer:

∆ RPQ

Step-by-step explanation:

__________________

Answer:

48

Step-by-step explanation: 1 foot is 12 inches. Since the feet are going up by ones, you can say 1=12, 2=24 (+12), 3=36(+12), 4=48(+12)

Hope this helps

Answer and Step-by-step explanation:

The answer is 48.

Each value of y is a multiple of 12, so for when there is 4 feet, you multiply 12 by 4 to get 48.

For when it is 1 foot, you multiply 12 by 1 to get 12.

For when it is 2 feet, you multiply 12 by 2 to get 24.

For when it is 3 feet, you multiply 12 by 3 to get 36

For when it is 5 feet, you multiply 12 by 5 to get 60.

If you were to continue, the y-values (aka the inches) will always be a multiple of 12.

#teamtrees #PAW (Plant And Water)

Answer:

65 degrees

Step-by-step explanation:

Angles in a triangle add to 180°.

Answer:

see below

Step-by-step explanation:   5  30   9   50

This is what I think they are asking for....

the zeroes are x = 0  x = -4    x = 7 twice ??       so

             x(x+4)(x-7)² = 0

when I graphed the function it looked to be correct

Answer:

3.$0.9

5.9:3 =3:1

Step-by-step explanation:

3.$5.40÷6=$0.9

Answer:

six equal to eight?????

Answer:

By the Central Limit Theorem, the mean is 78, the standard deviation is [tex]s = \frac{6}{\sqrt{n}}[/tex] and the shape is approximately normal.

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 78 and a standard deviation of 6

This means that [tex]\mu = 78, \sigma = 6[/tex]

Samples of n:

This means that the standard deviation is:

[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{6}{\sqrt{n}}[/tex]

What are the mean, standard deviation, and shape of the distribution of x-bar for n?

By the Central Limit Theorem, the mean is 78, the standard deviation is [tex]s = \frac{6}{\sqrt{n}}[/tex] and the shape is approximately normal.

Answer:

8.4%

Step-by-step explanation:

let x = interest rate

55,000(1 + x)^16 = 200,000

divide both sides by 55,000

(1 + x)^16 = 3.636

find the invese of 16

1 + x = 1.084

x = 0.084

x = 8.4

Answer:

too much salt will not bring taste to the cup cakes

Step-by-step explanation:

The best i could find out is 450p

Answer:

Candice

Step-by-step explanation:

The degree for 7pi/4 is : 315°

Answer:

0.1771

Step-by-step explanation:

total number of cards in a deck : 52

number of face card per suite : 3

total number of suites : 4 (hearts, clubs, diamonds, spades)

3 * 4 = total number of face cards

12/52 = 0.23 = probability of drawing a face card

remaining card are non face cards

52-12 = 40

40 non face cards

40/52 = 0.77 = probability of drawing a non face card

probability of drawing a face card followed by a non face card

multiply probabilities together to find combined probability

probability of drawing a face card * probability of drawing a non face card

= 0.23 * 0.77

= 0.1771

Answer:

2) <TWN and <SWM

Step-by-step explanation:

2) <TWN and <SWM

Answer:

(2)

Step-by-step explanation:

This is because they are both vertical to one another!

Hope this helps!

Answer:

9

Step-by-step explanation:

0.001 · 9 = 0.009

Answer: I asked my teacher, she said it is c

Step-by-step explanation:

Answer:

yes it's c

have a great day

210 - 30 = 180

180 ÷ 15 = 12

12 weeks

It would take her 12 weeks to pay for the DVD player.

Answer:

1 = 100% probability that a person will wait for more than 33 minutes.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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.

The mean waiting time is 55 minutes and the variance of the waiting time is 11.

This means that [tex]\mu = 55, \sigma = \sqrt{11}[/tex]

Find the probability that a person will wait for more than 33 minutes.

This is 1 subtracted by the p-value of Z when X = 33. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{33 - 55}{\sqrt{11}}[/tex]

[tex]Z = -6.63[/tex]

[tex]Z = -6.63[/tex] has a p-value of 0.

1 - 0 = 1

1 = 100% probability that a person will wait for more than 33 minutes.

Answer:

The probability of you choosing S would be a 1/11 chance or a 0.0909090909 chance.

Answer:

1 / 11

Step-by-step explanation:

there are 11 letters in candlesick so 11 possibilities and 1 S which is 1 out of 11 or 1 / 11.

Hope this helps ( :

Answer:

B

Step-by-step explanation:

Depreciates 14% per year so 100% - 14% is 86% or 0.86. Formula is (principal)(rate)^ years

Answer:

I think it is b) 70

Step-by-step explanation:

Arrange the numbers in ascending order then find the middle number.

Answer:

70

Step-by-step explanation:

Write down all the data points: 20, 40, 50, 70, 80, 90, 110 and identify which is in the very middle.

Answer:

n = [tex]5\frac{4}{5}[/tex]

Step-by-step explanation:

You obviously have to solve for n

Answer:

AB = 9

Step-by-step explanation:

Here is a simple case of a proportion.

We see that:

3:4

x:12

what can we do to make 4 into 12?

we multiply it by 3

so we do the same to 3

3*3=9

Answer:

I think C. is it

Step-by-step explanation:

Answer:

Step-by-step explanation:

8 is not a function

9 is a function

10 is a function

9514 1404 393

Answer:

  7x^3 +11x^2 -5x -8

Step-by-step explanation:

Combine like terms.

  (4x^3+6x^2+2x^2-3) + (3x^3+3x^2-5x-5)

  = (4 +3)x^3 +(6 +2 +3)x^2 +(-5)x + (-3 -5)

  = 7x^3 +11x^2 -5x -8

_____

Noting that the first expression contains two x^2 terms, we wonder if you actually want the sum ...

  (4x^3+6x^2+2x-3) + (3x^3+3x^2-5x-5)

  = (4 +3)x^3 +(6 +3)x^2 +(2 -5)x +(-3 -5)

  = 7x^3 +9x^2 -3x -8