Answer:
The 95 percent Confidence Interval is for the population is (38.911 , 41.089)
Step-by-step explanation:
To solve the above question, we would be making use of the confidence interval formula:
Confidence Interval = Mean ± z score × σ/√n
In the above question,
Mean = 40
σ = Standard deviation = 5
n = number of samples = 81
Confidence Interval = 95%
The z score for a 95% confidence interval = 1.96
Therefore, the confidence interval =
= 40 ± 1.96 (5/√81)
= 40 ± 1.96(5/9)
= 40 ± 1.0888888889
Confidence Interval
a)40 + 1.0888888889
= 41.0888888889
Approximately = 41.089
b ) 40 - 1.0888888889
= 38.911111111
Approximately = 38.911
Therefore, the 95 percent Confidence Interval is for the population is (38.911 , 41.089)
simplify each expression 17x + 4 - 3x
Answer:
14x+4
Step-by-step explanation:
17x-3x=14x
what percent of sales were shoes or socks? A.9% B. 39% C.52% D. 61%
Answer:
it is 9%
Step-by-step explanation: the socks persent is the correct answer
Answer: D. 61%
Step-by-step explanation:
Open the graphing tool. Move the slider for the equation y = kx3 to a position of your choice, where k ≠ 1. Next, move the slider of y = (kx)3 so the two graphs lie on top of one another. How do the values of k compare with one another in this situation? Why do you think that is?
Answer:
For the functions to coincide, the value of k in y = (kx)3 must be smaller than in y = kx3. This is because the value of y changes more rapidly when k is cubed inside the parentheses. The behavior of the functions is similar since a vertical stretch is similar to a horizontal compression.
Step-by-step explanation:
PLATO
The cost, C, in United States Dollars ($), of cleaning up x percent of an oil spill along the Gulf Coast of the United States increases tremendously as x approaches 100. One equation for determining the cost (in millions $) is:
Complete Question
On the uploaded image is a similar question that will explain the given question
Answer:
The value of k is [tex]k = 214285.7[/tex]
The percentage of the oil that will be cleaned is [tex]x = 80.77\%[/tex]
Step-by-step explanation:
From the question we are told that
The cost of cleaning up the spillage is [tex]C = \frac{ k x }{100 - x }[/tex] [tex]x \le x \le 100[/tex]
The cost of cleaning x = 70% of the oil is [tex]C = \$500,000[/tex]
Now at [tex]C = \$500,000[/tex] we have
[tex]\$ 500000 = \frac{ k * 70 }{100 - 70 }[/tex]
[tex]\$ 500000 = \frac{ k * 70 }{30 }[/tex]
[tex]\$ 500000 = \frac{ k * 70 }{30 }[/tex]
[tex]k = 214285.7[/tex]
Now When [tex]C = \$900,000[/tex]
[tex]x = 80.77\%[/tex]
Help me please please please please
Answer:
1.
d. (-14) + (-8)
2.
a. (-14) + 8
Step-by-step explanation:
(-14) - 8 is equal to (-14) + (-8) because we still add two negative values so the result wouldn't change.
(-14) - (-8) is equal to (-14) + 8 because there's two negative sign in front of 8 and two negative values multiplied makes a positive result.
Answer:
1. D
2. A
Step-by-step explanation:
1. It asks you what expression has the same value as (-14)-8. All you need to do is find other equations that have the same value as that. So the equation is -14-8. IF a negative is outside a parenthesis with a positive number inside like -(+5), it is going to be -5. If it's both negative: -(-5), it will be +5. If it is both positive: +(+5), it is going to be +5.
IMPORTANT!
- and + = -
- and - = +
+ and + = +
What we are looking for: -14-8
So choice A is (-14)+8 which is simplified to -14+8. So, this one isn't right.
Choice B: 14-(-8)= 14+8. So, it's incorrect.
Choice C: 14+(-8)= 14-8. Again, it's not -14-8 so it's not right.
Choice D: (-14)+(-8)= -14-8. This equation matches the one we are looking for! So it's correct!
2. Same thing as number 1. Let's simplify the equation it wants us to find first.
(-14)-(-8)= -14+8
So -14+8 is what we are looking for.
Choice A: (-14)+8= -14+8. It matches! So it is correct. Let's look at the other options anyway.
Choice B: 14-(-8)= 14+8. Nope. Not right.
Choice C: 14+(-8)= 14-8 because - always beats +. So, this one is also incorrect.
Choice D: (-14)+(-8)= -14-8. Oops, this is also wrong. So choice A is the right answer.
Keep in mind, when you start getting questions like this with numbers inside the parenthesis as well, you want to remember the same rules for positive and negative, but also multiply the numbers together:
(When there is a number outside and inside a parentheses, multiply them.)
2(5)=10, CORRECT! 2+(5) is not 2 times 5. It's whatever is closest to the parentheses, in this case being the positive sign. So + and 5 is just 5!
IMPORTANT!
-2(-5)= - and - is positive, so positive (2 times 5). Positive 10.
-2(+5)= - and + is negative, so negative (2 times 5). Negative 10.
+2(+5)= + and + is positive, so positive (2 times 5). Positive 10.
What is the error in this problem
Answer:
12). LM = 37.1 units
13). c = 4.6 mi
Step-by-step explanation:
12). LM² = 23² + 20² - 2(23)(20)cos(119)°
LM² = 529 + 400 - 920cos(119)°
LM² = 929 - 920cos(119)°
LM = [tex]\sqrt{929+446.03}[/tex]
= [tex]\sqrt{1375.03}[/tex]
= 37.08
≈ 37.1 units
13). c² = 5.4² + 3.6² - 2(5.4)(3.6)cos(58)°
c² = 29.16 + 12.96 - 38.88cos(58)°
c² = 42.12 - 38.88cos(58)°
c = [tex]\sqrt{42.12-20.603}[/tex]
c = [tex]\sqrt{21.517}[/tex]
c = 4.6386
c ≈ 4.6 mi
HELP NEED PRECALC HELP WILL GIVE BRAINLIEST PLEASE HELP
From your earlier questions, we found
[tex]2\sin(4\pi t)+5\cos(4\pi t)=\sqrt{29}\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)[/tex]
so the wave has amplitude √29. The weight's maximum negative position from equilibrium is then -√29, so you are solving for t in the given interval for which
[tex]\sqrt{29}\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)=-\dfrac{\sqrt{29}}2[/tex]
Divide both sides by √29:
[tex]\sin\left(4\pi t+\tan^{-1}\left(\dfrac52\right)\right)=-\dfrac12[/tex]
Take the inverse sine of both sides, noting that we get two possible solution sets because we have
[tex]\sin\left(\dfrac{7\pi}6\right)=\sin\left(\dfrac{11\pi}6\right)=-\dfrac12[/tex]
and the sine wave has period 2π, so [tex]\sin x=\sin(x+2\pi)=\sin(x+4\pi)=\cdots[/tex].
[tex]\implies 4\pi t+\tan^{-1}\left(\dfrac52\right)=\dfrac{7\pi}6+2n\pi[/tex]
OR
[tex]\implies 4\pi t+\tan^{-1}\left(\dfrac52\right)=\dfrac{11\pi}6+2n\pi[/tex]
where n is any integer.
Now solve for t :
[tex]t=\dfrac{\frac{7\pi}6+2n\pi-\tan^{-1}\left(\frac52\right)}{4\pi}[/tex]
OR
[tex]t=\dfrac{\frac{11\pi}6+2n\pi-\tan^{-1}\left(\frac52\right)}{4\pi}[/tex]
We get solutions between 0 and 0.5 when n = 0 of t ≈ 0.196946 and t ≈ 0.363613.
Please help me I will mark brainliest! The ratio of the number of boys to the number of girls in a school is 3:4. One-third of the boys and three-eighths of the girls wear spectacles, If there are 612 pupils who do not wear spectacles, a)find the total number of the pupils in the school, and b) how many more girls than boys are there in the school
Answer:
a) 952
b) 136
Step-by-step explanation:
Ratio of b:g = 3:4, based on this we have:
Number of boys = 3xNumber of girls = 4xTotal number of pupils = 3x+4x = 7xNumber of spectacle wearers:
1/3*3x + 3/8*4x = x + 3/2x = 2.5xNumber of those not wearing spectacles:
7x - 2.5x= 4.5xAnd this number equals to 612, then we can find the value of x:
4.5 x = 612x= 612/4.5x= 136a) Total number of pupils:
7x = 7*136 = 952b) The difference in the number of boys and girls:
4x-3x= x = 136Answer:
total number of students: 952
number of girls more than boys :136 more girls
Step-by-step explanation:
1/3 of boys +3/8 girls= spectacles
612 people do not wear spectacles
3:4= boys: girls
total number of students
3+4=7
boys + girls = total ratio
7= total ratio
1/3×3=1 3/8×4=3/2
1+3/2=5/2
7-5/2=9/2 9/2=612 students
If 9/2=612 Then 7=?
7= 7÷ 9/2×612
=952 people
Girls more than boys
if 7= 952
3= 3/7 × 952=408 boys
if 7 = 952
4= 4/7 ×952=544girls
Girls - boys
544- 408 = 136 girls
Which of the following expression is equal to X^2+9
Answer:
(x + 3i) * (x - 3i) = x^2 + 3xi - 3xi - 9(i^2) = x^2 + 9
Step-by-step explanation:
Determine which is the appropriate approach for conducting a hypothesis test. Claim: The mean RDA of sodium is 2400mg. Sample data: n150, 3400, s550. The sample data appear to come from a normally distributed population.
Answer:
Use the student t distribution
Step-by-step explanation:
Here is the formula
t = (x - u) ÷(s/√N)
From the information we have in the question:
n = 150
s = 550
x = 3400
u = mean = 2400
= 3400 - 2400÷ 500/√150
= 1000/44.9
= 22.27
At 0.05 significance level, df = 149 so t tabulated will be 1.65.
We cannot use normal distribution since we do not have population standard deviationWe cannot use normal distribution since we do not have population standard deviationChisquare cannot be used since we are not testing for population varianceWe cannot use normal distribution since we do not have population standard deviationChisquare cannot be used since we are not testing for population varianceThe parametric or bootstrap method cannot be used either.In order to purchase a new backyard patio in 3 years, the Robinsons have decided to deposit $1,700 in an account that earns 6% per year compounded monthly for 3 years. How much money will be in the account in 3 years?
Answer: A = 2,034.356 ≈ $2,034.36
$2,034.36 will be in the account in 3 years
Step-by-step explanation:
Given that ;
P = $1,700
Rate r = 6%
Time period (t) = 3 years
now to find how much money will be in the account in 3 years
we say;
A = P ( 1 + r/n )^nt
A = 1,700 ( 1 + 0.06/12) ¹²ˣ³
A = 1,700 ( 1.19668)
A = 2,034.356 ≈ $2,034.36
Assume a significance level of alpha = 0.05 and use the given information to complete parts (a) and (b) below. Original claim: The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm. The hypothesis test results in aP-value of 0.2761.a. State a conclusion about the null hypothesis.(Reject H0 or fail to reject H0.) Choose the correct answer below.A. Fail to reject H0 because the P-value is less than or equal to alphaα.B. Reject H0 because the P-value is less than or equal to alphaα.C.Fail to reject H0 because the P-value is greater than alphaα.D. Reject H0 because the P-value is greater than alphaα.b. Without using technical terms, state a final conclusion that addresses the original claim. Which of the following is the correct conclusion?A. The standard deviation of pulse rates of the group of adult males is more than 11 bpm.B. There is not sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.C. The standard deviation of pulse rates of the group of adult males is less than or equal to 11 bpm.D. There is sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.
Answer:
a
The correct option is B
b
The correct option is D
Step-by-step explanation:
From the question we are told that
The level of significance is [tex]\alpha = 0.05[/tex]
The p-value is [tex]p = 0.2761[/tex]
Considering question b
Given that the [tex]p< \alpha[/tex] then the null hypothesis is rejected
Considering question b
Given that the original claim is The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm
Then the null hypothesis is [tex]H_o : \sigma = 11[/tex]
The reason why the null hypothesis is write like this above is because a null hypothesis expression can not contain only a > or a < but only allows = [tex]\le , \ and \ \ge[/tex]
and the alternative hypothesis is [tex]H_a : \sigma > 11[/tex]
Now given that the null hypothesis is rejected, it mean that there is sufficient evidence to support original claim
Solve for x in the equation below. Round your answer to the nearest hundredth. Do not round any intermediate computations. 12-8x=5
Answer:
x = 0.88Step-by-step explanation:
[tex]12-8x=5\\\\Collect\:like\:terms\\\\-8x =5-12\\\\-8x = -7\\\\Divide\:both\:sides\:by -8\\\frac{-8x}{-8} \\=\frac{-7}{-8} \\\\x = 0.875\\\\x = 0.88[/tex]
The sequence below represents Marisa’s fine at the library for each day that she has an overdue book: $0.50, $0.65, $0.80, $0.95, $1.10, ... Which equation represents Marisa’s library fine as a function of a book that is n days overdue? f(n) = 0.15n f(n) = 0.50n f(n) = 0.15n + 0.35 f(n) = 0.50n + 0.15
Answer:
f(n) = 0.15n + 0.35Step-by-step explanation:
The sequence of the problem above is an arithmetic sequence
For an nth term in an arithmetic sequence
F(n) = a + ( n - 1)d
where a is the first term
n is the number of terms
d is the common difference
To find the equation first find the common difference
0.65 - 0.5 = 0.15 or 0.80 - 0.65 = 0.15
The first term is 0.5
Substitute the values into the above formula
That's
f(n) = 0.5 + (n - 1)0.15
f(n) = 0.5 + 0.15n - 0.15
The final answer is
f(n) = 0.15n + 0.35Hope this helps you
Answer:
The correct option is: f(n) = 0.15n + 0.35Step-by-step explanation:
Took the math test on edge
In the number 5,794,032,861, which digit is in the ten millions place?
09
0 5
o 7
0 4
In a random sample of people, the mean driving distance to work was miles and the standard deviation was miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a % confidence interval for the population mean . Interpret the results. Identify the margin of error.
Complete Question
In a random sample of ten people, the mean driving distance to work was 23.1 miles and the standard deviation was 6.6 miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 99% confidence interval for the population mean Interpret the results. Identify the margin of error.
Answer:
The 99% confidence interval is [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
The margin of error is [tex]E = 6.783[/tex]
Step-by-step explanation:
From the question we are told that
The sample mean is [tex]\= x = 23.1[/tex]
The standard deviation is [tex]\sigma = 6.6 \ miles[/tex]
The sample size is n = 10
Generally the degree of freedom is mathematically represented as
[tex]df = n-1[/tex]
=> [tex]df = 10-1[/tex]
=> [tex]df =9[/tex]
Given that the confidence level is 99% , the n the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha =1\%[/tex]
[tex]\alpha =0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] with a df of 9 from from the student t-distribution table the value is
[tex]t _{\frac{\alpha }{2} , df } = 3.250[/tex]
Generally the margin of error is mathematically represented as
[tex]E = t_{\frac{\alpha }{2} , df } * \frac{\sigma }{\sqrt{n} }[/tex]
[tex]E = 3.250 * \frac{6.6 }{\sqrt{10} }[/tex]
[tex]E = 6.783[/tex]
The 99% confidence interval is
[tex]\= x - E < \mu < \= x + E[/tex]
=> [tex]23.1 - 6.78 < \mu <23.1 + 6.78[/tex]
=> [tex]16.32< \mu <29.88[/tex]
The interpretation is that there is 99% confidence that the true mean lies within the limits
Look at parallelogram below d1 and d3 Are both 35 degrees what is the measurement of d2
Answer:
145 degrees
Step-by-step explanation:
Adjacent angles in a parallelogram are supplementary.
d2 = 180° -d1 = 180° -35°
d2 = 145°
Solve for y:1(y+3)=2(y+−4)+−7
Answer:
[tex]\large \boxed{{y=18}}[/tex]
Step-by-step explanation:
[tex]1(y+3)=2(y+-4)+- 7[/tex]
Expand brackets.
[tex]y+3=2y-8+- 7[/tex]
Simplify.
[tex]y+3=2y-15[/tex]
Add -y and 15 on both sides.
[tex]y+3-y+15=2y-15-y+15[/tex]
Simplify.
[tex]3+15=2y-y[/tex]
[tex]18=y[/tex]
Answer:
18
Step-by-step explanation:
● 1 (y+3) = 2 (y+(-4) )+ (-7)
When you multiply by 1 you get the same result.
● y+3 = 2 (y+(-4))+(-7)
When you have a + sign with a - sign write -.
● y+3 = 2(y-4)-7
Multiply 2 by (y-4) and simplify
● y+3 = (2y-8)-7
● y+3 = 2y -8-7
● y+3 = 2y -15
Add 15 to both sides
● y +3+15 = 2y-15 +15
● y + 18 = 2y
Sibstract y from both sides
● y +18 - y = 2y -y
● 18 = y
An oblique cone has a radius of 5 units and a height of 9 units. What is the approximate volume of the oblique cone? Use π ≈ 3.14 and round to the nearest tenth. 117.8 cubic units 141.3 cubic units 235.5 cubic units 282.6 cubic units
Answer:
235.6 units^3
Step-by-step explanation:
The formula for the volume of the oblique cone is the same as for the volume of a right circular cone: V = (1/3)(base area)(height).
Here that comes to V = (1/3)(π)(5 units)^2*(9 units), or
V = 75π units^3, or approximately 235.6 units^3
Answer:
235.5 cubic units
Step-by-step explanation:
The accompanying summary data on total cholesterol level (mmol/l) was obtained from a sample of Asian postmenopausal women who were vegans and another sample of such women who were omnivores.
Diet Sample Size Sample Mean Sample SD
Vegan 85.00 5.20 1.08
Omnivore 91.00 5.65 1.10
Calculate a 99% CI for the difference between the population mean total cholesterol level for vegans and population mean total cholesterol level for omnivores. (Use μvegan−μomnivore). Round to three decimal places.)
Interpret the interval.
a. We are 99% confident that the true average cholesterol level for vegans is less than that of omnivores by an amount within the confidence interval.
b. We are 99% confident that the true average cholesterol level for vegans is greater than that of omnivores by an amount within the confidence interval.
c. We are 99% confident that the true average cholesterol level for vegans is greater than that of omnivores by an amount outside the confidence interval.
d. We cannot draw a conclusion from the given information.
Answer: hey
Step-by-step explanation:
In a frequency distribution of 290 scores, the mean is 99 and the median is 86. One would expect this distribution to be:
Answer:
positively skewed to the right
Step-by-step explanation:
The measure of the central tendency is a profound way to describe the mean, median and mode. The measure of central tendency indicates where the center of distribution tends to be. The measure of central tendency provide a validity and answers whether the scores are high or generally low.
In this measure,The mean is usually pulled to the tail. The skewed is determined by where the tail goes, to the right side , it is positively skewed and to the left side , it is known as negatively skewed distribution.
Given that:
In a frequency of distribution of 290 scores,
the mean = 99
the median = 86
One would expect this distribution to be; positively skewed to the right since the mean value is greater than the median value.
In the figure below.. Please help!!!
====================================================
Explanation:
Both AB and XY are the first two letters of ABC and XYZ respectively. So we have one fraction of AB/XY = 2/7.
AC and XZ are the first and last letters of ABC and XYZ respectively. We can form another fraction AC/XZ. I'm dividing in the same order of small over large to keep things consistent. As you can probably guess, the order of the letters ABC and XYZ are important so we see how the angles match up and how the proportional sides match up.
Because the triangles are similar, the two fractions formed earlier are equal to one another.
The equation we need to solve is AB/XY = AC/XZ
-----
AB/XY = AC/XZ
2/7 = 3/N ... plug in given values
2N = 7*3 .... cross multiply
2N = 21
N = 21/2 .... divide both sides by 2
N = 10.5
ZX is 10.5 units long.
6th grade math. :) help me please
Answer:
8 3/4
Step-by-step explanation:
The decimal 3.5 as an improper fraction is 35/10.
Answer:
[tex]8\frac{3}{4}[/tex]
Step-by-step explanation:
To write as a mixed number means that you will have a whole number and a fraction together. To find the mixed fraction version, see how many times the denominator (bottom) fits into the numerator (top) evenly.
4, 8, 12, 16, 20, 24, 28, 32, 36
1 2 3 4 5 6 7 8 9
4 can go into 35 '8' times without being greater than the numerator. 8 is the whole number. Now subtract the original numerator by the product of 4 and 8, which is 32:
[tex]35-32=3[/tex]
3 is the new numerator. Keep the same denominator. Insert all values:
[tex]\frac{35}{4}=8\frac{3}{4}[/tex]
:Done
Help please
I don’t know what it is and I need to find the value of x please HELP
Answer:
[tex]\large \boxed{x\° = 130}[/tex]
Step-by-step explanation:
The triangle is an isosceles triangle. The base angles are equal.
Angles in a triangle add to 180 degrees.
[tex]y+65+65=180\\y+130=180\\y=50[/tex]
Angles on a straight line add up to 180 degrees.
[tex]x+50=180\\x=130[/tex]
Answer:
[tex]\huge\boxed{\sf x = 130\ degrees}[/tex]
Step-by-step explanation:
The measure of exterior angle is equal to the sum of non-adjacent interior angles.
So,
x = 65 + 65
x = 130 degrees
i need help really bad
Answer:
see explanation
Step-by-step explanation:
If f(x) and [tex]f^{-1}[/tex] are inverse functions, then
f([tex]f^{-1}[/tex])(x) = x
Thus substitute x = [tex]f^{-1}[/tex] (x) into f(x)
f([tex]\frac{x+6}{5}[/tex] )
= 5 ([tex]\frac{x+6}{5}[/tex] ) - 6
= x + 6 - 6
= x
Thus f(x) and [tex]f^{-1}[/tex] (x) are inverse functions
Find the value of x that will make L || M
Answer:
x = 7
Step-by-step explanation:
L and M would be parallel if angle 2x -3 and the angle x + 4 are equal.
Thus, 2x - 3 = x + 4, so that x = 7
3a-27=0
How to solve
Answer:
a = 9
Step-by-step explanation:
3a - 27 = 0
3a = 27
a = 27/3
a = 9
3*9 - 27 = 0
27 - 27 = 0
Answer:
a = 9
Step-by-step explanation:
3a-27=0
Add 27 to each side
3a = 27
Divide by 3
3a/3 = 27/3
a = 9
what is the equation for a parabola with a focus at (2,2) and a directix of x=8
Answer:
( y-5) ^2 =-12(x-2)
Step-by-step explanation:
focus at (2,2) and a directrix of x=8
Using the equation
( y-k) ^2 = 4p(x-k)
where ( h,k) is the vertex
The vertex is 1/2 way between the focus and the directrix
( 2+8)/2 , 2
5,2 is the vertex
( y-5) ^2 = 4p(x-2)
distance from the focus to the vertex and from the vertex to the directrix is
| p|
2-5 = p
-3 = p
( y-5) ^2 = 4*-3(x-2)
( y-5) ^2 =-12(x-2)
. One sample has M = 18 and a second sample has M = 14. If the pooled variance for the two samples is 16, what is the value of Cohen’s d?
Answer:
Cohen's d : 1.00
Step-by-step explanation:
We know that M₁ = 18, and M₂ = 14. Given that the pooled variance for the these two samples are 16, S²Pooled = 16, and therefore S - pooled = 4.
The formula to solve for the value of Cohen's d is as follows,
d = M₁ - M₂ / S - pooled,
d = 18 - 14 / 4 = 4 / 4 = 1
Therefore the value of Cohen's d = 1
If you have $100 in a savings account earning 3% interest per year, how much will you have in
two years?
Answer:
$106
Step-by-step explanation:
You have 100$ in savings account
Interest rate =3%
Time = 2 years
Total in 2 years:
100 + 2*3% = 100 *1.06= $106The interest formula is as follows:
Amount Invested · Rate = Interest Earned
If we invest $100 at 3% interest per year,
how much do we earn that year?
Well based on our formula, we can simply multiply 100 · 3%.
Think of the 3% as 3/100.
So we have 100 · 3/100 and the 100's cancel and we're left with 3.
So $3 is earned in 1 year.
So after two years, you will have double that or $6.