Answer:
(a)[tex]e^{-0.000428 t}[/tex]
Step-by-step explanation:
We are given that
Half life of radium-226=1620 yr
The quantity left Q(t) after t years is given by
[tex]Q(t)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]
a. We have to convert the given function into an exponential function using base e.
[tex]Q(t)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]
=[tex]((\frac{1}{2})^t)^{\frac{1}{1620}[/tex]
=[tex]e^{ln(1/2) t/1620}[/tex]
[tex]=e^({\frac{ln(1/2)}{1620}t)[/tex]
=[tex]e^{-0.000428 t}[/tex]
(b)
[tex]Q(0)=e^{-0.000428 \times 0}[/tex]
=1
From original function
Q(0)=1
[tex]Q(1620)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]
[tex]Q(1620)=\frac{1}{2}=0.5[/tex]
From exponential function
[tex]Q(1620)=e^{-0.000428 \times 1620}[/tex]
[tex]=0.499\approx 0.5[/tex]
[tex]Q(3240)=(\frac{1}{2})^{\frac{3240}{1620})=0.25[/tex]
[tex]Q(3240)=e^{-0.000428 \times 3240}[/tex]
Q(3240)=0.249=[tex]\approx 0.25[/tex]
Hence, verified.
18- 3 x 2/5 - 12
Could someone help me with this?
Answer:
I hope it helps u.......
Find the probability
Answer:
[tex]\frac{1}{5}[/tex]
Step-by-step explanation:
Red: 2
Blue: 4
Yellow: 4
[tex]\frac{2}{10}[/tex]
[tex]\frac{2/2}{10/2}=\frac{1}{5}[/tex]
Use technology to help you test the claim about the population mean, mu, at the given level of significance, alpha, using the given sample statistics. Assume the population is normally distributed.
Claim: μ>1220;α=0.08; σ=211.67.
Sample statistics: x=1235.91,n=300
Identify the null and alternative hypotheses and calculate the standardized test statistic.
Answer:
H0 : μ = 1220
H1 : μ > 1220
Test statistic = 1.30
Step-by-step explanation:
Sample mean, x = 1235.91
Standard deviation, σ = 211.67
Sample size, n = 300
The hypothesis :
Null ; H0 : μ = 1220
Alternative ; H1 : μ > 1220
Tbe test statistic :
(x - μ) ÷ (σ/√(n))
(1235.91 - 1220) ÷ (211.67/√(300))
15.91 / 12.220773
= 1.3018
= 1.30
In the sale, Mo buys a jacket for $63.
The original price was reduced by 25%.
Calculate the original price of the jacket.
Answer:
$84
Step-by-step explanation:
63÷3=21
63+21=84
Hope this helps! :)
fill in the blanks the 2 digit largest whole number is______
If m and n are two rational numbers, then m+n lies between m and n
2
Answer:
19thuuzvdkedhddudhjdhdhfghfidhdhdhfheidhfjr9fddy6gqufgaqgxhrhrydudkydtdffyztstdtiztuytzmyrsyrststststsut0egjjefeigjeojokfzbkehfzifgihrxeudihxizhieg9zfjz9deffejfjiefeihfiefhiefhefiefh3fr3hi3jfhfhfkzdhf2ivuvdfuvuzfecfkfidyfl5a4
Need help with this question
Answer:
cant see it
Step-by-step explanation:
just type it out
Rachel is driving to visit her mother, who lives 250 miles away. How long will the
drive be, round-trip, if Rachel drives at an
average speed of 40 mph?
Answer:
Time for a round trip = 12.5 hours
Step-by-step explanation:
Mother's house = 250 miles
Total distance for the round trip = 250 + 250 = 500 miles
Given speed = 40 mph
Find time .
[tex]Speed = \frac{distance }{Time }\\\\Time = \frac{distance }{speed } = \frac{500}{40} \\\\Time = 12.5 \ hours[/tex]
A desk is on sale for $368 , which is 36% less than the regular price.
What is the regular price? PLEASE SHOW EXACTLY HOW TO DO THIS
The regular price of the desk found using the discount and the selling price is $575.
What is meant by the discount rate of an item?
Discount pricing is a form of promotional pricing strategy where the original cost of a good or service is decreased in an effort to draw more customers, move inventory, and boost sales. Consumers adore feeling as though they are getting a fantastic bargain, which is why they are lured to reduced costs. The selling price is the price at which the good or commodity has actually been sold, whereas the marked price is the cost set by the seller in accordance with market norms. The buyer claims to have received a discount when the selling price is less than the marked price.
Given,
The selling price of the desk = $368
The percentage of discount = 36%
Let the regular price be x.
then we can write the following equation,
x - 36% of x = 368
x - 0.36x = 368
0.64x = 368
x = $575
Therefore the regular price of the desk found using the discount and the selling price is $575.
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ANSWER ASAP PLS!!!!!
A scientist is studying the growth of a particular species of plant. He writes the following equation to show the height of the plant f(n), in cm, after n days:
f(n) = 10(1.02)n
Part A: When the scientist concluded his study, the height of the plant was approximately 11.04 cm. What is a reasonable domain to plot the growth function? (4 points)
Part B: What does the y-intercept of the graph of the function f(n) represent? (2 points)
Part C: What is the average rate of change of the function f(n) from n = 1 to n = 5, and what does it represent? (4 points)
Answer:
see below
Step-by-step explanation:
f(n) = 10(1.02)^n
Part A
Let f(n) = 11.04
11.04 = 10 * 1.02 ^n
Divide each side by 10
11.04/10 = 1.02^n
1.104 = 1.02^n
Taking the log of each side
log 1.104 = log 1.02^n
We know log a^b = b log a
log 1.104 = n log 1.02
log 1.104 / log 1.02 = n
4.99630=n
Rounding n to 5
The domain should be 0 ≤n≤5
Part B
f(n) = 10(1.02)^n
The function is in the form y =a b^x where a is the y intercept
The y intercept is 10. This is the value when n =0 days.
Part C
To find the average rate of change
f(5) - f(1)
-----------
5-1
f(5) = 11.04
f(1) = 10 *1.02 =10.2
11.04 - 10.2
-----------
5-1
.84
-----
4
.21 cm per day
The average rate of growth over the 4 days is .21 cm per day
Answer:
Part A: A reasonable domain to plot the growth of the function would be: 0 < n < 5.
Part B: The y-intercept of the graph of the function f(n) represents the height of the plant in 0 days when it first began.
Part C: The average rate of change of the function from n = 1 to n = 5 is 0.84 or 0.21cm per day. It represents the amount of growth for the plant over 4 days.
, Hope this helps :)
Have a great day!!
When testing gas pumps for accuracy, fuel-quality enforcement specialists tested pumps andfound that 1304 of them were not pumping accurately (within 3.3 oz when 5 gal ispumped),and 5689 pumps were accurate. Use a 0.01 significance level to test the claimof an industryrepresentative that less than 20% of the pumps are inaccurate.
Answer:
The p-value of the test statistic from the standard normal table is 0.0017 which is less than the level of significance therefore, the null hypothesis would be rejected and it can be concluded that there is sufficient evidence to support the claim that less than 20% of the pumps are inaccurate.
Step-by-step explanation:
Here, 1304 gas pumps were not pumping accurately and 5689 pumps were accurate.
x = 1304, n = 1304 + 5689 = 6993
The level of significance = 0.01
The sample proportion of pump which is not pumping accurately can be calculated as,
The claim is that the industry representative less than 20% of the pumps are inaccurate.
The hypothesis can be constructed as:
H0: p = 0.20
H1: p < 0.20
The one-sample proportion Z test will be used.
The test statistic value can be obtained as:
[tex]Z=\frac{\hat{p}-P}{\sqrt{\frac{P(1-P))}{n}}}\\\\Z=\frac{0.186-0.20}{6993}\\\\Z=-2.927[/tex]
If 82 pages had between 7 and 9 errors, what was the approximate total number of pages in the book?
A: 202 pages
B: 120 pages
C: 68 pages
D: 56 pages
Answer:
120 pages
Step-by-step explanation:
The mean number of error per page = 8 ; Standard deviation = 1
Given that :
82 pages has between 7 and 9 errors per page ;
Using the empirical rule :
7 = 8 - 1 = 1 standard deviation below the mean
9 = 8 + 1 = 1 standard deviation above the mean
1 standard deviation from the mean = 68%
Hence, 82 pages = 68%
Approximate total pages :
68% = 82
100% = total pages, x
0.68 = 82
1 = x
0.68x = 82
x = 82 / 0.68
x = 120.588
Hence, total number of pages is 120 pages
he speeds (in MPH) of automobiles traveling in a city are given below:
20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58
The mean speed of the cars is
Answer:
Mean speed = 41.3 mph
Step-by-step explanation:
Given that,
The speeds of an automobiles are given below:
20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58
We need to find the mean speed of the cars.
Mean = sum of observations/ no. of observation
[tex]M=\dfrac{20+35+42+52+65+49+24+37+23+41+50+58}{12}\\\\M=41.3[/tex]
So, the mean speed of the cars is equal to 41.3 mph.
Evaluate if 8y + 4x – (2x + 3) if x = – 2 and y = 6
Answer:
41
Step-by-step explanation:
substitute x=-2 and y=6, we know
8×6 +4×(-2) -(2×(-2) +3) = 48-8-(-1) =41
Answer:
41
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightStep-by-step explanation:
Step 1: Define
Identify
8y + 4x - (2x + 3)
x = -2
y = 6
Step 2: Evaluate
Substitute in variables: 8(6) + 4(-2) - (2 · -2 + 3)(Parenthesis) Multiply: 48 - 8 - (-4 + 3)(Parenthesis) Add: 48 - 8 - (-1)Subtract: 41she sells 6adult tickets and 5 children tickets on the first day totaling $112.50 and on the second day she sells 8adult tickets and 4 childrens tickets totaling $130. write an equation for each day and use the elimination method
Answer:
Cost of adult ticket = $12.5
Cost of child ticket = $7.5
Step-by-step explanation:
Given:
Cost of 6 adult ticket and 5 child ticket = $112.5
Cost of 8 adult ticket and 4 child ticket = $130
Find:
Equation and solution
Computation:
Assume;
Cost of adult ticket = a
Cost of child ticket = b
So,
6a + 5b = 112.5....eq1
8a + 4b = 130 ......eq2
Eq2 x 1.25
10a + 5b = 162.5 .....eq3
eq3 - eq1
4a = 50
Cost of adult ticket = $12.5
8a + 4b = 130
8(12.5) + 4b = 130
Cost of child ticket = $7.5
The distance between two points is 10 units, if the coordinates of one of the endpoints are (4, -7), find x if the coordinates of the other endpoint are (x, 1).
Answer:
10
Step-by-step explanation:
let the distance = d
d² = (x2-x1)² + (y2-y1)²
=>
10²= (x-4)²+(1+7)²
100 = (x-4)²+64
(x-4)²=100-64
= 36
x-4 = √36
x-4=6
x= 6+4
x= 10
I need help I’ll give u brainlest
Answer:
216 yd³
Step-by-step explanation:
Volume of a rectangular prism
= product of the three orthogonal sides
= 6yd * 6yd * 6yd
= 216 yd³
Answer:
216
Step-by-step explanation:
:)
Solve the compound inequality 7x ≥ –56 and 9x < 54.
Answer: first one is x≥-8 second one is x<6
Step-by-step explanation: for the first one you divide both sides by 7 and the second won do the same except divide by 9 on each side
Hello,
7x ≥ -56
⇔ 7x / 7 ≥ -56 / 7
⇔ x ≥ -8
S = [-8 ; +∞[
9x < 54
⇔ 9x / 9 < 54 / 9
⇔ x < 6
S = ]-∞ ; 6]
:-)
which of the following is the quotient of the rational expressions shown below? x/3x-1 divided by x-2/2x ?
Answer:
Below.
Step-by-step explanation:
x/3x-1 divided by x-2/2x
= x/3x-1 * 2x/x-2
= 2x^2/(3x-1)(x-2).
If we expand the denominator it is
2x^2/(3x^2-7x+2).
Consider the polygon defined by the coordinates A(−3, 5), B(3, 7), C(6, −2), and D(0, −4). Which statements are correct?
A) Area of ABCD = 60 units2
B) AB = 60 units
C) CD = 40 units
D) BC = 80 units
E) Perimeter of ABCD ≈ 31.6 units
Answer:
A,C,E
Step-by-step explanation:
Can anyone please help me
Answer:
The experiment shows the frequency of results derived from tossing a coin
A landscaper is making a garden bed in the shape of a rectangle. The length of the garden bed is 2.5 feet longer than twice the width of the bed. The area of the garden bed is 62.5 square feet. What is the perimeter of the garden bed, in feet?
Answer:
I'll setup the problem, then you can do the calculations
Step-by-step explanation:
Perimeter = 2width(W) + 2length (L)
Area = LW
L = 2.5 + 2W
LW = 62.5
substitute L in equation for area
[tex]2.5W + {2W}^{2} = 62.5 \\ \\ {2W}^{2} + 2.5 - 62.5 \\ \\ use \: quadratic \: solution \\\frac{ - b ± \sqrt{ {b}^{2} - 4ac}}{2a} [/tex]
a = 2; b = 2.5; c = 62.5
send a comment if you have a question
The perimeter of a rectangle.
P = 2 ( length + width )
The area of a rectangle.
Area = length x width
The perimeter of the rectangle shape garden bed is 32 feet.
What is a rectangle?A rectangle is a two-dimensional shape where the length and width are different.
The area of a rectangle is given as:
Area = Length x width
We have,
A rectangular shape Landscaper:
Width = W
Length = 2.5 + W
Area = 62.5 square feet
The perimeter of a rectangle.
P = 2 ( length + width )
The area of a rectangle.
Area = length x width
Now,
Area = 62.5
length x width = 62.5
(2.5 + W) x W = 62.5
2.5W + W² = 62.5
W² + 2.5W = 62.5
W² + 2.5W - 62.5 = 0 ______(A)
The roots of this equation (A) are:
W = 6.75 and W = -9.25 (eliminated)
Now,
Length = 2.5 + 6.75 = 9.25 feet
Width = 6.75 feet
The perimeter of the rectangle.
P = 2 ( length + width )
P = 2 x (9.25 + 6.75)
P = 2 x 16
P = 32
Thus,
The perimeter of the rectangle shape garden bed is 32 feet.
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Value of 140 degree in diagrams
Answer:
There are 360º in a circle. 140º has been allocated to one angle.
There are 360-140 = 220º left in the circle.
Step-by-step explanation:
simplify 4-x squared ÷2x-x squared
Answer:
4-[tex]\frac{x}{2}[/tex]-[tex]x^{2}[/tex]
Step-by-step explanation:
The length of a rectangle should be 8 meters longer than 7 times the width. If the length must be
between 43 and 106 meters long, what are the restrictions for the width, x?
Answer:
The restrictions for x would be 14 > x > 5.
Step-by-step explanation:
Let the length of the rectangle be y and the width be x.
That being said, the equation would be as follows:
[tex]y = 7x + 8[/tex]
[tex]y - 8 = 7x[/tex]
[tex]x = \frac{y-8}{7}[/tex]
Therefore, substituting the two values of y into the equations, we would get:
[tex]x = \frac{43-8}{7}[/tex]
[tex]x = \frac{35}{7}[/tex]
[tex]x = 5[/tex]
And:
[tex]x = \frac{106-8}{7}[/tex]
[tex]x = \frac{98}{7}[/tex]
[tex]x = 14[/tex]
Therefore, x would be between 5 and 14, and the restrictions for x would be 14 > x > 5.
Hope this helped!
How do you find the surface area
Answer:
It depends on what shape you have. Here are some formulas for different shapes.
Step-by-step explanation:
Rectangular prism: 2lw + 2lh + 2wh
Cylinder: 2 pi r² + 2 pi rh
Sphere: 4 pi r²
Cone: pi r² + pi rl
Square-based pyrimid: 1/2lp +B
I hope this helps!
Can anybody help me with this problem regarding Line Integrals (Calc 3)?
Compute ∫F*dr, given the counterclockwise unit circle C : cos((pi)t), sin((pi)t), t∈[0,2] and the vector field F(x,y) = (y²,-x²)
The line integral is
[tex]\displaystyle \oint_C\mathbf F(x,y)\cdot\mathrm d\mathbf r = \int_0^2 \mathbf F(x(t),y(t))\cdot\frac{\mathrm d\mathbf r}{\mathrm dt}\,\mathrm dt \\\displaystyle= \int_0^2 (\sin^2(\pi t),-\cos^2(\pi t))\cdot(-\pi\sin(\pi t),\pi\cos(\pi t))\,\mathrm dt \\\displaystyle=-\pi\int_0^2(\sin^3(\pi t)+\cos^3(\pi t))\,\mathrm dt = \boxed{0}[/tex]
Mrs. Smith bought 6.2 kg of cassava and 1 kg 250 g of bananas. What is the total weight in kg?
Step-by-step explanation:
my answer is in the image above
The volume of a right cylinder is 277 cubic centimeters, and the
height is 3 centimeters (cm). What is the radius of the cylinder?
Answer:
3cm
use the formula for the volume of a cylinder
and substitute
Which represents where f(x) = g(x)