The expense ratio (in percentage) for large-cap growth mutual funds have the following sample data0.52, 1.06, 1.26, 2.17, 1.55, 0.99, 1.10, 1.07, 1.81, 2.05 0.91, 0.79, 1.39, 0.62, 1.52, 1.02, 1.10, 1.78, 1.01, 1.15The data is believed to be normally distributed.a. Is there compelling evidence for concluding that the population mean expense ratio exceeds 1%? Carry out a test of the relevant hypothesis using a significance level 0.01.b. Referring back to part (a), describe in context type I and II errors and say which error you might have made in reaching your conclusion. The source from which the data was obtained reported that ? = 1.33 for the population of all 762 such funds. So did you actually commit an error in reaching your conclusion?c. Suppose that ? = 0.5, determine and interpret the power of the test in part (a) for the actual value of ? stated in (b).
Answer:
Part a: Since the calculated value of t = 2.412 does not fall in the critical region t > ± 2.539 we conclude that population mean expense ratio does not exceed 1% at 0.01 significance level.
Part b: Yes we accepted the null hypothesis when it is false so we made a type II error.
Part c: Power = 0.6591=0.66
Step-by-step explanation:
Part a:
Let the null and alternate hypotheses be
H0: u ≤ 1 against the claim Ha: u > 1
The significance level is ∝=0.01
As the standard deviation of the population is not given we use t- test which has n-1= 20-1= 19 degrees of freedom
This is one tailed test the critical region is t > ± 2.539
The mean is calculated to be 1.24 and standard deviation of the sample = s= 0.4486
We take population mean = u= 1
The test statistic is
t = x`-u/ s/ √n
t= 1.24-1 / 0.445/√20
t= 0.24/0.0995
t= 2.412
Since the calculated value of t = 2.412 does not fall in the critical region t > ± 2.539 we conclude that population mean expense ratio does not exceed 1% at 0.01 significance level.
Part b:
Type I errors are those errors when the null hypothesis is true and is rejected.
Type II errors are those in which the null hypothesis is false and is accepted.
If we had rejected the null hypothesis as it was true then we would have made a type I error.
Population mean = u = 1.33
And our null hypothesis is u= 1
Yes we accepted the null hypothesis when it is false so we made a type II error.
Part c:
When σ= 0.5
For Part a: μ= 1.33
Power = P (reject H0/ H0 is false)
= 1-β
P (reject H0/ H0 is false) = P (z > 2.539+ (u`-u0) / σ*√n)
= P (z > 2.539+ (1-1.33) /0.5 *√20)
=P (z > 2.539-2.9516)
= P (z > 0.4126)
= 0.5 - P (z= 0.2938) from the area of table.
= 0.5- 0.1591
=0.3409
Power = 1-β = 1- 0.3409= 0.6591=0.66
The U.S. Department of Agriculture records data on farm acreage and number of farms by county for every county in the country. This takes considerable time and energy, and the results for each update (usually occurring approximately every five years) are a long time in process. A quicker way to update the data is by sampling. The table below shows the number of counties in each geographic region and a summary of farm acres (in thousands) for independent random samples of 22 counties from each region.
Region Number of counties
North Central 1052
North East 210
South 1376
West 418
Required:
a. Estimate the mean acreage for each region, with a margin of error.
b. Estimate the total acreage for each region, with a margin of error.
c. Estimate the difference between mean acreage for the North Central region and the South, with a margin of error.
d. Estimate the difference between mean acreage for the North East and the West, with a margin of error.
e. Estimate the mean acreage per county across the United States, with a margin of error.
Solution :
From the table,
Number of countries = [tex]$N_i$[/tex]
Mean = [tex]$\overline Y_i$[/tex]
Standard deviation = [tex]$\sigma_i$[/tex]
Margin of error of B = 50,000 acres
So we determine the [tex]$\text{sample size n}$[/tex] and then allocate the four regions of [tex]$n_1, n_2, n_3$[/tex] and [tex]$n_4$[/tex].
Under the [tex]$\text{proportional allocation}$[/tex], the [tex]$\text{equation}$[/tex] for the value of [tex]$n_1$[/tex] which yields [tex]$V(\overline Y_{st}) = D = \frac{B^2}{H}$[/tex] is given by :
[tex]$n=\frac{\sum_{K=1}^L N_K \sigma^2_K}{ND+\frac{1}{N}\sum_{K=1}^L N_K \sigma^2_K}$[/tex]
Let us complete the numerator
[tex]$\sum_{K=1}^L N_K \sigma^2_K = N_1\sigma_1^2 + N_2\sigma_2^2 + N_3\sigma_3^2 + N_4\sigma_4^2$[/tex]
[tex]$= 1052 \times (271)^2 + 210 \times (79)^2 + 1376 \times (244)^2 + 418 \times (837)^2 $[/tex]
= 453329920
The bound on the error of estimation is B = 50,000 acres
Hence we get
[tex]$D=\frac{B^2}{H}$[/tex]
[tex]$=\frac{50000^2}{4}$[/tex]
= 625,000,000
[tex]$n=\frac{\sum_{K=1}^L N_K \sigma^2_K}{ND+\frac{1}{N}\sum_{K=1}^L N_K \sigma^2_K}$[/tex]
[tex]$=\frac{453329920}{3056 \times 625 + \frac{1}{3056} \times 453329920}$[/tex]
= 220.24044
≈ 221 (approximately)
Therefore, the sample size under the proportional allocation from each stratum are given by :
[tex]$n_1=n\left[\frac{N_1}{\sum_{K=1}^\mu N_K}\right]$[/tex]
[tex]$=221\left[\frac{1052}{3056}\right]$[/tex]
≈ 76
[tex]$n_2=n\left[\frac{N_2}{\sum_{K=1}^\mu N_K}\right]$[/tex]
[tex]$=221\left[\frac{210}{3056}\right]$[/tex]
≈ 15
[tex]$n_3=n\left[\frac{N_3}{\sum_{K=1}^\mu N_K}\right]$[/tex]
[tex]$=221\left[\frac{1376}{3056}\right]$[/tex]
≈ 100
[tex]$n_4=n\left[\frac{N_4}{\sum_{K=1}^\mu N_K}\right]$[/tex]
[tex]$=221\left[\frac{418}{3056}\right]$[/tex]
≈ 30
Thus, we should select 76 counties from North central region, 15 counties from the north east region, 100 from south region and 30 from west region.
We can also estimate mean acreage of each county across all the county with a margin of error of 50,000 acres.
Solve the system of equations.
2y+7x=−5
5y−7x=12
We can solve this by substitution method.
Look at the second equation. If we rearrange to find 7x, we can substitute in the value into the first equation.
[tex]5y-7x=12[/tex]
[tex]5y-7x-12=0[/tex]
[tex]5y-12=7x[/tex]
Therefore, [tex]7x=5y-12[/tex]
Now replace the 7x in the first equation with 5y - 12:
[tex]2y+7x=-5[/tex] (substitute in 7x = 5y - 12)
[tex]2y+(5y-12)=-5[/tex]
[tex]7y-12=-5[/tex]
[tex]7y=7[/tex]
[tex]y=1[/tex]
Now that we know y, we can find x by substituting in y = 1 into any equation we want. I will use the equation: 7x = 5y - 12
[tex]7x=5y-12[/tex] (substitute in y = 1)
[tex]7x=5(1) -12[/tex]
[tex]5x=5-12[/tex]
[tex]7x=-7[/tex]
[tex]x=-1[/tex]
__________________________________________________________
Answer:
[tex]y=1\\x=-1[/tex]
Eight new graduates are hired by an engineering firm. Each is assigned at random to one of eight cubicles arranged in a row in the back of the room that houses the engineering staff. Two of the graduates are Bill and Cathy. What is the probability that they are assigned adjacent cubicles
Answer:
the probability that they are assigned adjacent cubicles is 1 ÷ 4
Step-by-step explanation:
Given that
There is 8 new graduates are hired
2 of the graduates are bill and cathy
And, each one is assigned on random basis
We need to find out the probability
So,
= (2) (7!) ÷ (8!)
= (2) ÷ (8)
= 1 ÷ 4
Hence, the probability that they are assigned adjacent cubicles is 1 ÷ 4
The same would be relevant
Solve the following: You purchase a set of Bluetooth earbuds for $45 and use a $5 off manufacturer's coupon. If sales tax is 8.25%, how much do you pay for the earbuds? Include the dollar sign in your answer and round to two decimal places.
Answer:
43.3
Step-by-step explanation:
45-5=40,
0.0825*40=3.3
40+3.3=43.3
So what would be the answer?
Answer:
i
Step-by-step explanation:
Answer:
did you forget a picture?
Step-by-step explanation:
if you did, either add it in the comments, or make a new question
if a +b+c = 0 then the value of a²+b²+c²/bc+ca+ab
pls solve and give the explanation
Answer:
[tex]\frac{a^2 + b^2 +c ^2}{a*b + a*c + b*c} = -2[/tex]
Step-by-step explanation:
if:
a + b + c = 0
then we can rewrite:
c = -a - b
Now we can replace this in our expression:
[tex]\frac{a^2 + b^2 + c^2}{a*b + a*c + b*c} = \frac{a^2 + b^2 + (-a - b)^2}{a*b + a*(-a - b) + b*(-a - c)}[/tex]
Now we can rewrite:
(-a - b)^2 = a^2 + 2*a*b + b^2
Then we can rewrite our expression as:
[tex]\frac{a^2 + b^2 + a^2 + b^2 + 2*a*b}{a*b - a^2 - a*b - b^2 - b*a}[/tex]
Let's keep simplifying this:
[tex]\frac{2*(a^2 + b^2 + a*b)}{-a*b - b^2 - a^2}[/tex]
Here is easy to see the simplification we need to do, as we have the same factor in the denominator as in the numerator (just a different of sign).
[tex]\frac{2*(a^2 + b^2 + a*b)}{-a*b - b^2 - a^2} = \frac{2*(a^2 + b^2 + a*b)}{-(a^2 + b^2 + a*b)} = -2[/tex]
Then the expression is equal to -2
[tex]\frac{a^2 + b^2 +c ^2}{a*b + a*c + b*c} = -2[/tex]
Please help!!! I am stressed so much!!
Answer:
You have to simplify the fraction and turn it into a decimal.
Step-by-step explanation:
Meaning: Make the fraction smaller and turn it into the correct decimal.
EXAMPLE:
2/4 simplified is 1/2
1/2 is equal to 0.50
The librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant took a sample and found the mean to be 880 books. She provides the librarian with an interval estimate of between 790 and 970 books checked out per day. An efficient, unbiased point estimate of the number of books checked out each day at the Library of Congress is
Answer:
a. 880
Step-by-step explanation:
Options are "a. 880 b. 90 c. 790 d. None of these choices"
Interval estimate of between 790 and 970 books checked out per day.
Lower limit is 790, Upper limit is 970
Point estimate of μ(x) = [Upper limit + Lower limit} / 2
Point estimate of μ(x) = [970 + 790] / 2
Point estimate of μ(x) = 1760/2
Point estimate of μ(x) = 880
So, the efficient, unbiased point estimate of the number of books checked out each day at the New York City Public Library is 880.
Which of the following is the point and slope of the equation y + 2 = 2(x - 8)?
-8, 2), 2
(2, -8), 2
(8, -2), 2
(-2, 8), 2
what is the volume of the aquarium?
Answer:
3000 in3 ? I haven't actually done this i-ready before- but I believe it's
Width x Length x Height = Final result?
Step-by-step explanation:
Can someone help me please???
Simplify.
(x^5)^4
Answer:
x^20 please mark me brainliest
Step-by-step explanation:
The Smiths painted their house blue. The complete predicate of this sentence is _____.
Smiths
the Smiths
If the perimeter of each of the seven regular hexagons in the figure shown is 24, what is the perimeter of the figure?
Answer:
the answer is 144(that is 6×24)
1 hundredth + 3 tenths =?hundredths
Answer:
.01 + .3 = 0.31
Step-by-step explanation:
Match each pair of Lines to the correct description
parallel lines
EP and CD
perpendicular lines
GH and EF
neither parallel nor
perpendicular lines
AB and CD
Answer:
Parallel = AB and CD
Perpendicular = EF and CD
Neither: GH and EF
Step-by-step explanation:
Parallel lines will go on forever without touching, they are aligned with each other.
Perpendicular lines intersect with 4 right angles
The Parallel lines are AB and CD and Perpendicular lines are EF and CD.
It is required to find the solution.
What is line?A line is a straight one-dimensional figure having no thickness and extending infinitely in both directions. A line is made of a set of points which is extended in opposite directions infinitely. It is determined by two points in a two-dimensional plane. The two points which lie on the same line are said to be collinear points.
Given:
The given figure shown as four lines are given AB , CD ,EF , CD ,GH and EF.
According to given question we have
Parallel = AB and CD
Perpendicular = EF and CD
Neither parallel nor perpendicular lines: GH and EF
Parallel lines are those lines that are equidistant from each other and never meet, no matter how much they may be extended in either directions
Perpendicular lines are lines that intersect at a 90-degree angle.
Therefore , the Parallel lines are AB and CD and Perpendicular lines are EF and CD.
Learn more details about Lines here:
https://brainly.com/question/2696693
#SPJ2
Mr. Halsey leans a ladder against an 11.5 foot wall the bottom the of the ladder is 3.5 ft from the base of the wall as shown what is the approximate length of the ladder
Hence, the approximate length of the ladder is [tex]12ft[/tex].
What is the approximation value?
An approximation is anything that is similar, but not exactly equal, to something else. A number can be approximated by rounding.
A calculation can be approximated by rounding the values within it before performing the operations.
Here given that,
[tex](x)^2=(11.5)^2+(3.5)^2\\X^2=132.25+12.25\\X^2=144.5 \\X=\sqrt{144.5}\\X=12 feet[/tex]
Hence, the approximate length of the ladder is [tex]12ft[/tex].
To know more about the approximation value
https://brainly.com/question/29580932
#SPJ2
What are the coordinates of the turning point of the parabola whose equation is y=-x^2+4x+1
PLEASEEE ANSWERRRRRR
Answer:
The maximum of the parabola lands at (2,5).
The coordinates of the turning point of the parabola whose equation is y=-x²+4x+1 are (2, 5)
What is Coordinate system?A coordinate system is a system that uses one or more numbers, or coordinates, to uniquely determine the position of the points.
The equation of Parabola is y=-x²+4x+1
The turning point (vertex) is the point where the derivative is equal to zero.
y=-x²+4x+1
Differentiate the equation
dy/dx=-2x+4
Now equate dy/dx with zero
dy/dx=0
-2x+4=0
-2x=-4
x=2
Now put x value in the equation
y=-(2)²+4(2)+1
y=-4+8+1
y=5
Hence the coordinates of the turning point of the parabola whose equation is y=-x²+4x+1 are (2, 5)
To learn more on Coordinate System click:
https://brainly.com/question/4726772
#SPJ2
Is 5pi/3 the same as 5/3 radians?
Best answer gets brainliest!!
Your class earned $110.00 Saturday afternoon by washing cars to raise money for a class trip. This is 14 of the money needed for the trip. What is the total amount needed?
Answer: $1,540.00 is the total amount needed for the class trip
Step-by-step explanation:
Data: $110.00 earned for class trip
14th of the money needed
Money needed: x
Step one, Make the equation
110x14=x
Reason: Since we know 110.00 is a 14th of the money needed, we know multipling it by 14 will get us the money needed for the class trip. Having it in an equation will make it easier to solve.
Step two, Evaluate the equation
110x14=x=1540=x
Reason: The only thing that was left to do was to multiply 110 by 14 to get 1540 since the x was already isolated to begin with. That leaves us with the answer of x=1540.
However, since this is a real world problem, we have to make the answer more realistic so the final answer is '$1,540.00 is the total amount needed for the class trip'
I hope this helps!
Please help me fast i need help
First question: less or greater
Second question: decrease or increase
Third question: would or would not
fourth question: correct or incorrect
You have to choose the answer's
Ok
Answer:
Look at the image.
Step-by-step explanation:
how is y=2x^2-8x+9 rewritten in vertex form.
9514 1404 393
Answer:
y = 2(x -2)^2 +1
Step-by-step explanation:
Start by factoring the leading coefficient from the x-terms.
y = 2(x^2 -4x) +9
Now identify the coefficient of x, -4, and figure half of that: -2. Square this number and add it inside the parentheses. At the same time, subtract the equivalent value outside parentheses. (The leading coefficient must be taken into account.)
y = 2(x^2 -4x +4) +9 -2(4)
Put in the desired form.
y = 2(x -2)^2 +1
This matches vertex form ...
y = a(x -h)^2 +k . . . . . . . . . vertical scale factor 'a'; vertex (h, k)
I have no idea pls help
Answer:
Area= 90
Step-by-step explanation:
triangle area: (b x h) / 2
(12 x 15) / 2
(180) / 2
a= 90
Donna is participating in a 6-day cross-country biking challenge. She biked for 51, 62, 61, 47, and 63 miles on the first five days. How many miles does she need to bike on the last day so that her average (mean) is 56 miles per day?
Answer:
52 miles
Step-by-step explanation:
total miles needed to average 56
56 * 6 = 336
miles after 5 days
51 + 62 + 61 + 47 + 63 = 284
miles needed on last day
336 - 284 = 52 miles
please help
thank you
Answer:
Step-by-step explanation:
-4<n≤5
PLEASE HELP 7TH GRADE MATH
BRAINLIEST-SHOWS WORK
PLEASE HELP
ANSWE 1 OR MORE AN WILL MARK BRAINLIEST 1 OR MORE
Answer:
Slope=-3/4
Step-by-step explanation:
The slope is the rise/run or y/x
Points given for A are (-4, 3), for B (4, -3)
The formula for slope is m=y^2-y^1/x^2-x^1
https://calcworkshop.com/graphing-linear-equations/slope-formula/
So we'll plug in the information given into the formula.
-4-4/3--3
-8/3+3
-8/6
so our slope is m=-3/4
Help Please?! ?????????????
Answer:
Ed's answer of [tex]\frac{3}{8}[/tex] is correct because he divided [tex]\frac{1}{4}[/tex] by [tex]\frac{2}{3}[/tex] to get his answer.
Step-by-step explanation:
To solve for m in [tex]\frac{2}{3}m=\frac{1}{4}[/tex] you want to isolate m by dividing by [tex]\frac{2}{3}[/tex] on both sides, therefore he divided [tex]\frac{1}{4}[/tex] by [tex]\frac{2}{3}[/tex] to get his answer of [tex]\frac{3}{8}[/tex], and his answer is correct.
Eve surveys the students in her classroom to find out how much time they spent doing their homework last night. The results are plotted in the line plot below. The measurements are rounded to the nearest \dfrac{1}{4}
4
1
start fraction, 1, divided by, 4, end fraction of an hour
Answer: The answer is 5/4 :)
Answer:
5/4 or 1 1/4
Step-by-step explanation:
khan academy
Find the surface area of the rectangular prism (type the number
only)
2.6
4.2 ft
6.8 ft
HELP
What is another way to write 5/5? *
Answer:
Hello! answer: 1
Step-by-step explanation:
5/5 is 1 whole so you could write it as 1 because 5/5 is worth 100%