Solve for x. Round to the nearest tenth, if necessary.
K

The percentage of the radioactive isotope left is 25.0000%.

The half life of a radioactive isotope is the time that will elapse before only half of the number of original isotopes will remain.

Now;

We are told that;

Half life (t1/2) = 55 days

Time taken (t) =  115 days

Ratio of isotope remaining = N/No

Thus;

N/No = (1/2)^t/t1/2

N/No = (1/2)^115/55

N/No = (1/2)^2

N/No =1/4

Hence, the percentage = 1/4 * 100/1 = 25.0000%

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The z-score for a score of 107 is 1.6

The given parameters are:

The z-score is calculated using:

[tex]z = \frac{x -\bar x}{\sigma}[/tex]

So, we have:

[tex]z = \frac{107 -95}{7.5}[/tex]

Evaluate the difference

[tex]z = \frac{12}{7.5}[/tex]

Divide

z = 1.6

Hence, the z-score is 1.6

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Answer:

-4(a + b = 6)

Step-by-step explanation:

When you multiply equation P by -4, you obtain -4a - 4b = -24. You can then add this equation to equation Q to eliminate the a term.

Answer:

⅝8⅝

Step-by-step explanation:

I made this with love and everything in the world of 9⁴⅝

Answer:

  6

Step-by-step explanation:

The equation of the line is written in the slope-intercept form:

  y = mx +b

where m is the slope and b is the y-intercept.

The given equation is ...

  y = 6x -9

Comparing this to the slope-intercept form, we see that ...

  m = 6

  b = -9

The slope of the line is m = 6.

The y-intercept is 3.78.

We have given that,

[tex]\overline{x}=7.8 ,S_x=3.70,\\\overline{y}= 12.2,S_y=4.15\\r=0.964[/tex]

[tex]Slope=r \times\frac{S_y}{S_x} \\\\Slope=0.964\times \frac{4.15}{3.70}\\ Slope=1.08=\overline{y}-slope\:\times \overline{x}\ intercept\\=\overline{y}-slope\:\times \overline{x}\\=12.2-1.08(7.8)\\=3.78[/tex]

Therefore the y-intercept is 3.78.

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The coefficient of determination is calculated as: 0.520.

The coefficient of determination = the square of the correlation coefficient.

Given the following:

Value of the linear correlation coefficient (r) = -0.721

Therefore, we would have:

The coefficient of determination = (-0.721)²

The coefficient of determination = 0.520

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Answer:

70/45

Step-by-step explanation:

(-10/9) divided by (-5/7)  = (-10/9) / (-5/7)

dividing two fractions is the same as multiplying the top fraction by the reciprocal of the bottom one

top fraction = -10/9

bottom fraction = -5/7

reciprocal just means switching the numerator and denominator

reciprocal of bottom fraction = 7 / -5 = -7/5

thus,

(-10/9) / (-5/7) = (-10/9) * reciprocal of (-5/7) = (-10/9) * (-7/5) = 70/45

note that to multiply two fractions, you just multiply the numerators to get your new numerator and do the same thing with the denominators

Answer:

a) 0.2098

b) 0.036

c) 0.1866

d) 0.9849

Step-by-step explanation:

Image is color coordinated for each part below,

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Through proportionality theorem.

By applying the concept of composition between two functions and utilizing the information given in the two tables, we find the following results: f ° g (0) = - 2, f ° g (x) = 1.

Compositions are binary operators between two functions: f - Former function, g - Latter function.

f ° g (x)

Where the input of the former function is the output of the latter function. By a brief observation, we find the following relationships in accordance with the two tables:

Case I

f(x):

0 → 1

g(x):

1 → - 2

Case II

f(x):

1 → 0

g(x):

0 → 1

By applying the concept of composition between two functions and utilizing the information given in the two tables, we find the following results: f ° g (0) = - 2, f ° g (x) = 1.

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The observation about the student's grade with the z score illustrated is that it's a half standard deviation above the mean of the total test score.

It should be noted that the z score is a numerical measurement which describes the relationship of a value to the mean value of the group.

In this case, the observation about the student's grade with the z score illustrated is that it's a half standard deviation above the mean of the total test score.

This is illustrated as the z score is 0.5.

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Answer:

if this is for edge unity the answer is B

Answer:

C.) cosZ=61/73

Step-by-step explanation:

I hope you got the answer

Answer:

f(x) = 800 - 75x

Step-by-step explanation:

Rachel took a loan of 800 dollars | Money Owed: f(x) = 800

She pays back 75 dollars a week <-> (x) | Money Owed: f(x) = 800 - 75x

The total number of ways the study can be selected is: 637065

Given,

Total number of women in a group= 13

Total number of men in a group = 12

Number of women chosen = 8

Number of men chosen = 8

∴ the total number of ways the study group can be selected = 13C₈ and 12C₈.

This in the form of combination factor = nCr

                                                     ∴ nCr = n!/(n₋r)! r!

13C₈ = 13!/(13 ₋ 8)! 8!

        = 13!/5!.8!

        = 1287

12C₈ = 12!/(12₋8)! 8!

        = 12!/5! 8!

        = 495

Now multiply both the combinations of men and women

= 1287 × 495

= 637065

Hence the total number of ways the study group is selected is 637065

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Answer:

Surface Area is equal to 160 cm²

here is your answer

Answer: formula

AB= (-1- -3)+((3-1)

(-1+3 )^2+(3-1)^2

2^2+2^2

Sq rt of 8 is 2.83

length of AB is 2

BC= (-3- -1)^2 + (5-3)^2

-3+1 =-2^2+2^2=4+4=8

Sq rt of 8 is 2.828= 2.83

Step-by-step explanation:

The data and assuming shows that the company that would give Donna a stable long-term investment is A. eye remember enterprises; the smaller deviation indicates that eye enterprises have less variability in its closing prices than masterful pocket watches.

It should be noted that the information given implies that Donna needs a stable long term investment.

In this case, it's appropriate that the company that has the less standard deviation should be chosen.

This illustrates that Perfect Plungers has less variability.

In conclusion, the correct option is A.

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Answer:

95 is the correct answer

Step-by-step explanation:

The initial or beginning side is H.  Look on the protractor and you will see the top number is 55 degrees.  That is where we start.  Now, go to line E, that is where we end.  The top number is 150.  To find <HEK, we need to subtract 55 from 150 to get 95.

The amount of energy absorbed by the pennies made up of copper is 146.25J

An equation is an expression that shows the relationship between two or more variables and numbers.

Amount of energy absorbed = mass * temperature change * specific heat capacity

Amount of energy absorbed = 25 * (38 - 23) * 0.39 = 146.25J

The amount of energy absorbed by the pennies made up of copper is 146.25J

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Answer: A. DC||AB

Step-by-step explanation:

Line DC is parallel to AB so the correct answer is option B.

If two objects are having the same shape then they will be termed as similar. So in mathematics, if two figures have the same shapes, lines or angles then they are called similar.

In the given image we can see that the two angles ABC and HCB are congruent to each other. So the line DC is parallel to AB.

Therefore Line DC is parallel to AB so the correct answer is option B.

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The simplified expression of axaxbxb is a^2b^2

The expression is given as;

axaxbxb

Rewrite properly as:

a * a * b * b

Evaluate the product

a^2b^2

Hence, the simplified expression of axaxbxb is a^2b^2

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Answer:

year 7 mean: ≈7.714

year 8 mean: 14

Step-by-step explanation:

mean = sum / number of observations

number of observations = 5, as there are 5 bars for each year

year 7 is the bar on the left for each day

observations for year 7:

5, 8, 9, 13, 19 (left to right)

sum = 5 + 8 + 9 + 13 + 19 = 54 for year 7

mean for year 7 = 54 / 7 ≈ 7.714

observations for year 8 (left to right):

10, 11, 18, 12, 19

sum = 10 + 11 + 18 + 12 + 19  = 70

mean = 70 / 5 = 14

Answer:

Step-by-step explanation:

$18. 50÷25=0. 74$

Step-by-step explanation:

the area of s circle is

pi×r²

r being the radius.

so, in our case

pi×17.8² = pi×316.84 = 995.3822164... ≈ 995 m²

[tex]\huge\underline{\red{A}\green{n}\blue{s}\purple{w}\pink{e}\orange{r} →}[/tex]

Step-by-step explanation:

As the given figure is a rectangle, therefore the opposite sides should be equal. So -

3x + y = 12 – y...(eqn (i) )

and

y – x = x – 1...(eqn (ii) )

Solving eqn (ii) we get -

→ y – x = x – 1

→ y = x + x – 1

→ y = 2x – 1...eqn(iii)

Solving eqn (i) we get -

→ 3x + y = 12 – y

→ 3x = 12 – y – y

→ 3x = 12 – 2y

Substituting the value of eqn (iii)

→ 3x = 12 – 2(2x– 1)

→ 3x = 12 – 4x + 2

→ 3x + 4x = 14

→ 7x = 14

→ x = 14/7

→ x = 2

Answer:

x = 2; y = 3

Step-by-step explanation:

Since the quadrilateral has 4 right angles, it is a rectangle.

In a rectangle, opposite sides are congruent.

3x + y = 12 - y

x - 1 = y - x

We have a system of two equation is 2 variables.

Let's simplify both equations.

3x + 2y = 12

2x - y = 1

Rewrite the first equation. Multiply both sides of the second equation by 2. Add the equations.

      3x + 2y = 12

(+)   4x - 2y = 2

-------------------------

      7x        = 14

Divide both sides by 2.

x = 2

Substitute 2 for x in the second original equation and solve for y.

x - 1 = y - x

2 - 1 = y - 2

1 = y - 2

y = 3

Answer: x = 2; y = 3

Answer:

5, 7

Step-by-step explanation:

The mode of the numbers is 5, which means that 5 should be the most common card (highest frequency). Therefore the cards should have at least one more 5 among them.

Considering that 5 is one of the hidden cards and x is the other,

• Using the equation for the mean:

[tex]mean = \frac{sum \space\ \space\ of \space\ \space\ numbers}{number \space\ \space\ of \space\ \space\ numbers}[/tex]

[tex]6 = \frac{4+5+ 9 + 5 + x}{5}[/tex]

⇒ [tex]30=23 + x[/tex]

⇒ [tex]x = 7[/tex]

This means 5 and 7 are the hidden cards.

The answer to the question that is modeled here is one sixth plus four sixths.

We have the following fractions

1/6 and 5/6

We are to find the fraction which when added to 1/6 would give us 5/6. Hence we have

1/6 + 4/6 = 5/6

Hence the correct answer to the question here is option a.

PLS HELP 1HOUR LEFT Select the expression that is modeled on the number line. A number line from zero to one partitioned into sixths. There are four hops beginning at one sixth and ending at five sixths one sixth plus five sixths

one sixth plus four sixths

five sixths minus one sixth

five sixths minus four sixths

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