Answer: [tex]30e^{0.00813x}[/tex]
Step-by-step explanation:
Given
Median age in 1980 is [tex]30[/tex]
It is [tex]35.3[/tex] in year 2000
Suppose the median age follows the function [tex]ae^{bx}[/tex]. Consider 1980 as starting year. Write the equation for year 1980
[tex]\Rightarrow 30=ae^{b(0)}\\\Rightarrow 30=a[/tex]
For year 2000
[tex]\Rightarrow 35.3=30e^{20b}\\\\\Rightarrow \dfrac{30e^{20b}}{30}=\dfrac{35.3}{30}\\\\\Rightarrow e^{20b}=1.17666\\\\\Rightarrow b=0.00813[/tex]
After t years of 1980
[tex]\Rightarrow 30e^{0.00813x}[/tex]
Can someone help me with this an my other work please?
Given the function
Calculate the following values:
Answer:
f(-1) = 1
f(0) = 20
f(2) = 38
Step-by-step explanation:
f(-1) = 9×-1 + 10 = -9 + 10 = 1
f(0) = 9×0 + 20 = 0 + 20 = 20
f(2) = 9×2 + 20 = 18 + 20 = 38
we needed to use the second definition for f(0), because that is the same as saying x=0.
and that is in the domain of the second function definition ( x>=0).
In a random sample of 26 residents of the state of Montana, the mean waste recycled per person per day was 2.8 pounds with a standard deviation of 0.23 pounds. Determine the 80% confidence interval for the mean waste recycled per person per day for the population of Montana. Assume the population is approximately normal. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answer:
The critical value that should be used in constructing the confidence interval is T = 1.316.
The 80% confidence interval for the mean waste recycled per person per day for the population of Montana is between 2.741 pounds and 2.859 pounds.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 26 - 1 = 25
80% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 25 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.8}{2} = 0.9[/tex]. So we have T = 1.316
The critical value that should be used in constructing the confidence interval is T = 1.316.
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.316\frac{0.23}{\sqrt{26}} = 0.059[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 2.8 - 0.059 = 2.741 pounds
The upper end of the interval is the sample mean added to M. So it is 2.8 + 0.059 = 2.859 pounds.
The 80% confidence interval for the mean waste recycled per person per day for the population of Montana is between 2.741 pounds and 2.859 pounds.
The owner of a golf course wants to determine if his golf course is more difficult than the one his friend owns. He has 8 golfers play a round of 18 holes on his golf course and records their scores. Later that week, he has the same 8 golfers play a round of golf on his friend's course and records their scores again. The average difference in the scores (treated as the scores on his course - the scores on his friend's course) is 9.582 and the standard deviation of the differences is 15.9274. Calculate a 90% confidence interval to estimate the average difference in scores between the two courses.1) (13.73,-0.65).2) (-10.359,-4.021).3) (-9.259,-5.121).4) (-13.745,-0.635).5) (13.745, -0.635).
Answer:
The 90% confidence interval to estimate the average difference in scores between the two courses is (-1.088, 20.252).
Step-by-step explanation:
We have the standard deviation for the differences, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 8 - 1 = 7
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 7 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.8946
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.8946\frac{15.9274}{\sqrt{8}} = 10.67[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 9.582 - 10.67 = -1.088
The upper end of the interval is the sample mean added to M. So it is 9.582 + 10.67 = 20.252
The 90% confidence interval to estimate the average difference in scores between the two courses is (-1.088, 20.252).
Find the angle between the vectors ????=????+???? and ????=−????+????. (Give an exact answer. Use symbolic notation and fractions where needed.)
Answer:
The angle between them is 60 degrees
Step-by-step explanation:
Given
[tex]a = 2i + j -3k[/tex]
[tex]b = 3i - 2j -k[/tex]
Required
The angle between them
The cosine of the angle between them is:
[tex]\cos(\theta) = \frac{a\cdot b}{|a|\cdot |b|}[/tex]
First, calculate a.b
[tex]a \cdot b =(2i + j -3k) \cdot (3i - 2j -k)[/tex]
Multiply the coefficients of like terms
[tex]a \cdot b =2 * 3 - 1 * 2 - 3 * -1[/tex]
[tex]a \cdot b =7[/tex]
Next, calculate |a| and |b|
[tex]|a| = \sqrt{2^2 + 1^2 + (-3)^2[/tex]
[tex]|a| = \sqrt{14[/tex]
[tex]|b| = \sqrt{3^2 + (-2)^2 + (-1)^2}[/tex]
[tex]|b| = \sqrt{14}[/tex]
Recall that:
[tex]\cos(\theta) = \frac{a\cdot b}{|a|\cdot |b|}[/tex]
This gives:
[tex]\cos(\theta) = \frac{7}{\sqrt{14} * \sqrt{14}}[/tex]
[tex]\cos(\theta) = \frac{7}{14}[/tex]
[tex]\cos(\theta) = 0.5[/tex]
Take arccos of both sides
[tex]\theta =\cos^{-1}(0.5)[/tex]
[tex]\theta =60^o[/tex]
Althea has $100. She divides it evenly among her 4 children. Her oldest child, Raul, spends $15 of the amount he receives. How much money does Raul have left after he spends $15?
Which statements about this word problem are true? Check all that apply.
This is an example of a part-whole problem.
This is an example of a comparison problem.
Addition then multiplication can be used to solve the problem.
Division then subtraction can be used to solve the problem.
Division then multiplication can be used to solve the problem.
Step-by-step explanation:
she gives each of her children $25 each,if Raul spends $15 then he would have $10 left.
Division then subtraction can be used to solve the problem.
What is mathematical expressions?An expression in mathematics is made up of numbers, variables, and functions (such as addition, subtraction, multiplication or division etc.) You can think of expressions as being comparable to phrases.
Given
she gives each of her children $25 each,if Raul spends $15 then he would have $10 left.
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The following data was collected from a survey in which people identified their average salaries over the past ten years. Identify the number of classes in the histogram.
Answer:
nine 9 classes in the histogram
A paper weight is made in the shape of a triangular pyramid.The dimensions of the paper weight are shown The formula for the volume of a triangular pyramid is V = 1/3 Bh .Which expression can be usef to find the value of B the area of the base of the pyramid
Answer:
[tex]B = \frac{3V}{h}[/tex]
Step-by-step explanation:
Given
[tex]V = \frac{1}{3}Bh[/tex]
Required
Solve for B
We have;
[tex]V = \frac{1}{3}Bh[/tex]
Multiply by 3
[tex]3V = Bh[/tex]
Make B the subject
[tex]B = \frac{3V}{h}[/tex]
What is the value of b?
Answer:
?
Step-by-step explanation:
The alternative hypothesis for a two-tailed test of a single population proportion might be?
A. Ha: P>0.4
B. Ha: P< 0.4
C. Ha: p~=0.4 (~means not equal to)
Answer:
tgis moght help
Step-by-step explanation:
https://opentextbc.ca/introbusinessstatopenstax/chapter/full-hypothesis-test-examples/
Two methods, A and B, are available for teaching Spanish. There is a 70% chance of successfully learning Spanish if method A is used, and a 85% chance of success if method B is used. However, method B is substantially more time consuming and is therefore used only 20% of the time (method A is used the other 80% of the time). The following notations are suggested:
A—Method A is used.
B—Method B is used.
L—Spanish was learned successfully. A person learned Spanish successfully.
What is the probability that he was taught by method A?
Answer:
0.7671 = 76.71% probability that he was taught by method A
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Person learned Spanish successfully.
Event B: Method A was used.
Probability of a person learning Spanish successfully:
70% of 80%(using method A)
85% of 20%(using method B)
So
[tex]P(A) = 0.7*0.8 + 0.85*0.2 = 0.73[/tex]
Probability of a person learning Spanish successfully and using method A:
70% of 80%, so:
[tex]P(A \cap B) = 0.7*0.8 = 0.56[/tex]
What is the probability that he was taught by method A?
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.56}{0.73} = 0.7671[/tex]
0.7671 = 76.71% probability that he was taught by method A
3.
Salary: A sales clerk receives a monthly
salary of $500 plus a commission of 6% on all
sales over $3500. What did the clerk earn the
month she sold $8000 in merchandise?
Answer:
Step-by-step explanation:
I might be wrong but it 1900 in merchandise
The clerk earned a total of $770 for the month she sold $8000 in merchandise.
To calculate the clerk's earnings for the month she sold $8000 in merchandise, we need to consider her monthly salary and commission.
The clerk's monthly salary is $500, which is a fixed amount.
For the commission, we need to calculate the sales amount that exceeds $3500. In this case, the sales amount exceeding $3500 is $8000 - $3500 = $4500.
The commission is calculated as 6% of the sales amount exceeding $3500. Therefore, the commission earned by the clerk is 6% of $4500.
Commission = 6/100 * $4500
Commission = $270
Adding the monthly salary and commission, we can calculate the clerk's total earnings for the month:
Total earnings = Monthly salary + Commission
Total earnings = $500 + $270
Total earnings = $770
Therefore, the clerk earned a total of $770 for the month she sold $8000 in merchandise.
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help me please i am struggle with this
uppose that the walking step lengths of adult males are normally distributed with a mean of 2.8 feet and a standard deviation of 0.2 feet. A sample of 76 men’s step lengths is taken. Step 1 of 2 : Find the probability that an individual man’s step length is less than 2.5 feet. Round your answer to 4 decimal places, if necessary.
Answer:
.0668
Step-by-step explanation:
Formula:
z=(x-average)/standard deviation
(2.5-2.8)/.2= -1.5
Go to a ztable and find the value for 1.5 (.9332) and take the compliment of this (we can do this because the normal distribution is symmetrical)
1-.9332= .0668
help me pleaseeeeeeeeeeeeeeeeee………….
Answer:
C
Step-by-step explanation:
200 x 5 = 1,000
100 x 10 = 1,000
C - 5 to 10 days
Answer:
C. 5 to 10 days
Step-by-step explanation:
If she drove 100 miles per day, then
1000/100 = 10
it took her 10 days.
If she drove 200 miles per day, then
1000/200 = 5
it took her 5 days.
Since she drove between 100 miles and 200 miles per days,
it took her from 5 to 10 days.
Answer: C. 5 to 10 days
The triangles are similar by??
the SAS similarity theorem
The of the matrix whose columns are vectors which define the sides of a parallelogram one another is the area of the parallelogram?
Answer:
absolute value of the determinant, adjacent to, equal to
Step-by-step explanation:
The absolute value of a determinant of the [tex]\text{matrix whose}[/tex] columns are the vectors and they define the [tex]\text{sides}[/tex] of a [tex]\text{parallelogram}[/tex] which is adjacent to one another and is equal to the [tex]\text{area}[/tex] of the [tex]\text{parallelogram}[/tex].
The determinant is a real number. They are like matrices, but we use absolute value bars to show determinants whereas to represent a matric, we use square brackets.
For this problem I believe the answer is option A, B and C. But just wanted to confirm. Is that correct or is my answer wrong?
Answer:
Just A and C
Step-by-step explanation:
B doesn't count because you would not be looking at the 9. Only the 4.
You only look at one number to the right.
Answer:
A and C are correct, but not B
Step-by-step explanation:
When you round, you only look at the number behind the place you are rounding.
6.04 doesn't round to 6.1, so that is not correct
Which point is on the line y=-2x+ 3?
(-2, -1)
( 3, -3)
(3, 3)
(-3, -9)
please give how you got your answer
Answer: (3, -3)
Step-by-step explanation:
You substitute each point into the function and see if it fits:
(-2, -1) ⇒ -2(-2) + 3 = 4 + 3 = 7 ≠ -1
(3, -3) ⇒ -2(3) + 3 = -6 + 3 = -3
(3, 3) ⇒ -2(3) + 3 = -6 + 3 = -3 ≠ 3
(-3, -9) ⇒ -2(-3) + 3 = 6 + 3 = 9 ≠ -9
if the mean of a random variable X is 45 what will be the mean of the sampling distribution of the sample mean?
Answer:
The mean of the sampling distribution is always equal to the mean of the population.
The mean of the sampling distribution of the sample mean is 45.
Given that,
The mean of the random variable X is 45.We need to find out the mean of the sampling distribution.Based on the above information, the calculation is as follows:
= mean of the random variable X
= 45
As the sampling distribution mean should always be equivalent to the population mean.
Therefore we can conclude that the mean of the sampling distribution of the sample mean is 45.
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In the coordinate plane, two vertices of square ABCD are A (0,0) and B (0, m). What are the coordinates of points C and D? Do not introduce any new variables.
Answer:
Step-by-step explanation:
As shown in the graph,
A, B, C and D are the vertices of a square, all sides of the square will be equal in measure.
Coordinates of A → (0, 0)
Coordinates of B → (0, m)
Distance between point D and point A = m
Therefore, coordinates of point D → (m, 0)
Now point C will be equally distant from the points B and D.
Coordinates of C → (m, m)
5x+2y=-3;x+5y=4
plz answer me
Answer:
x = -1 and y = 1
Step-by-step explanation:
5x + 2y = -3 . . . . . . . (i)
x + 5y = 4 . . . . . . . (ii)
Finding x in terms of y from eq. (ii) :-x + 5y = 4
x = 4 - 5y
Placing this value of x in eq. (i) :-5(4 - 5y) + 2y = -3
20 - 25y + 2y = -3
-23y = - 23
y = 1
Placing the value of y in eq. (i)5x + 2(1) = -3
5x + 2 = -3
5x = - 5
x = -1
Express each ratio as a fraction in its lowest terms.
18 hours to 2 days
Answer:
3/8.
Step-by-step explanation:
First convert days to hours:
2 days = 2 * 24 = 48 hours.
The greatest common factor of 18 and 48 = 6 so the required fraction is
18/48
= (18/6) / (48/6)
= 3/8.
If f(x) is a linear function, what is the value of n?
х
_4
f(x)
---25
-10
-1
n
20
2
оооо
9
Step-by-step explanation:
You can simply plot these points on a graph and see where the line goes. It go
evaluate the expression when b=3
y = -7
4b-y
Answer:
5
Step-by-step explanation:
Given :
b = 3 y = -7To Find :
Value of 4b - y .Solution:
Put on the respective values ,
⇒ 4b - y = 4 × 3 - 7
⇒ 4b - y = 12 - 7
⇒ 4b - y = 5
Hence the required answer is 5 .
Answer: 5
Step-by-step explanation:
We can plug in the numbers for variables. So, our new equation would becomes 4x3-7. We first evaluate 4x3=12. Then, 12-7=5. Hence, your answer is 5.
Thane Company is interested in establishing the relationship between electricity costs and machine hours. Data have been collected and a regression analysis prepared using Excel. The monthly data and the regression output follow:
Month Machine Hours Electricity Costs
January 2,300 $ 19,100
February 2,700 $ 22,400
March 1,700 $ 14,200
April 2,900 $ 24,400
May 3,600 $ 28,950
June 3,100 $ 23,400
July 3,900 $ 25,450
August 3,300 $ 23,450
September 1,800 $ 16,900
October 3,500 $ 27,400
November 4,500 $ 32,400
December 4,000 $ 28,450
Summary Output
Regression Statistics
Multiple R 0.957
R Square 0.917
Adjusted R2 0.908
Standard Error 1,586.26
Observations 12.00
Coefficients Standard Error t Stat P-value Lower 95% Upper 95%
Intercept 5,970.52 1,766.77 3.38 0.01 2,033.90 9,907.13
Machine Hours 5.76 0.55 10.49 0.00 4.54 6.98
The percent of the total variance that can be explained by the regression is:
Answer:
0.924
Step-by-step explanation:
R² = 0.854
R = √0.854
R = 0.924
Hence, the correlation Coefficient of electricity tarrif is 0.924 ; this correlation Coefficient value, depicts a strong positive correlation between machine hours and cost of electricity. And can he interpreted to mean that ; Electricity tarrif increases as machine hours increases and also decreases as machine hours decreases.
Which expression is equivalent to the difference shown?
Answer:
Option A. -1/20x
Step-by-step explanation:
[tex] \frac{5x + 1}{5x} - \frac{4x + 1}{4x} [/tex]
[tex] = \frac{20x + 4x - 20x - 5x}{20x^{2} } [/tex]
[tex] = \frac{ - x}{20x^{2} } [/tex]
[tex] - \frac{1}{20x} [/tex]
Answered by GAUTHMATH
Larry deposits $15 a week into a savings account. His balance in his savings account grows by a constant percent rate.
True
False
Answer:
The answer is true
Step-by-step explanation:
Jen recently rode her bicycle to visit her friend who lives 6 miles away. On her way there, her average speed was & miles per hour faster than on her way home. If jen
spent a total of 2 hours bicycling find the two rates.
Answer:
(1) +t+=+1.2+ hrs
Step-by-step explanation:
Find the appropriate answer for each word problem.
a. A group of twelve art students are visiting a local art museum for a field trip. The total cost of admission for the students is $125. What is the cost of admission for each student?
b. The school van can carry twelve passengers at a time. What is the least number of trips the van must make in order to bring 125 passengers to the same location?
c. Charlotte and her mother baked 125 cookies to give as Christmas gifts to their neighbors. If they plan to give a dozen cookies to each neighbor, how many neighbors will receive a gift?
d. Nicholas and Elaine are planning to serve cheesecake for dessert at their wedding and have purchased twelve cheesecakes. If the cheesecakes are divided evenly among the 125 wedding guests, how much cheesecake will each guest receive?
I WILL GIVE BRAINLIEST IF CORRECT
Answer:
a. $10
b. 10.46
c. 10.46
d. 0.096
