Male bluethroats have a complex song which is thought to be used to attract female birds. Let x denote the duration of a randomly selected song (in seconds) from a male bluethroat. The authors of research on bluethroat song report the mean song duration is 13.8 seconds and the standard deviation of song durations is 11.8 seconds. The authors also noted that the song length distribution is not normal.
Required:
a. Let = average song duration (in seconds) for a sample of 36 male bluethroat songs. Is this distribution of the sample mean song duration " normally distributed" ?
b. Find the probability that a sample of 36 male bluethroat songs will have a mean duration greater than 12 seconds. Draw, label, and shade a graph to illustrate your result.
Answers
Answer:
a) Sample size larger than 30, so by the Central Limit Theorem, yes.
b) 0.8199 = 81.99% probability that a sample of 36 male bluethroat songs will have a mean duration greater than 12 seconds. The sketch is given at the end.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean song duration is 13.8 seconds and the standard deviation of song durations is 11.8 seconds.
This means that [tex]\mu = 13.8, \sigma = 11.8[/tex]
Sample of 36
This means that [tex]n = 36, s = \frac{11.8}{\sqrt{36}} = 1.9667[/tex]
a. Let = average song duration (in seconds) for a sample of 36 male bluethroat songs. Is this distribution of the sample mean song duration " normally distributed" ?
Sample size larger than 30, so by the Central Limit Theorem, yes.
b. Find the probability that a sample of 36 male bluethroat songs will have a mean duration greater than 12 seconds. Draw, label, and shade a graph to illustrate your result.
This is 1 subtracted by the p-value of Z when X = 12. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{12 - 13.8}{1.9667}[/tex]
[tex]Z = -0.915[/tex]
[tex]Z = -0.915[/tex] has a p-value of 0.1801.
1 - 0.1801 = 0.8199
0.8199 = 81.99% probability that a sample of 36 male bluethroat songs will have a mean duration greater than 12 seconds.
Sketch:
Related Questions
look at the image below
Answers
If a $6 per unit tax is introduced in this market, then the new equilibrium quantity will be
Answers
Answer:
soory i dont know just report me if you angry
What are 3 ratios that are equivalent to 8 :5
Answers
Answer:
Step-by-step explanation:
8/5 = 16/10 = 24/15
8:5 = 16:10 = 24:15
Suppose that a local TV station conducts a survey of a random sample of 120 registered voters in order to predict the winner of a local election. The Democrat candidate was favored by 62 of the respondents.
Required:
a. Construct and interpret a 99% CI for the true proportion of voters who prefer the Republican candidate.
b. If a candidate needs a simple majority of the votes to win the election, can the Republican candidate be confident of victory? Justify your response with an appropriate statistical argument.
Answers
Answer:
a) The 99% CI for the true proportion of voters who prefer the Republican candidate is (0.3658, 0.6001). This means that we are 99% sure that the true population proportion of all voters who prefer the Republican candidate is (0.3658, 0.6001).
b) The upper bound of the confidence interval is above 0.5 = 50%, which meas that the candidate can be confidence of victory.
Step-by-step explanation:
Question a:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
Sample of 120 registered voters in order to predict the winner of a local election. The Democrat candidate was favored by 62 of the respondents.
So 120 - 62 = 58 favored the Republican candidate, so:
[tex]n = 120, \pi = \frac{58}{120} = 0.4833[/tex]
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4833 - 2.575\sqrt{\frac{0.4833*0.5167}{120}} = 0.3658[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4833 + 2.575\sqrt{\frac{0.4833*0.5167}{120}} = 0.6001[/tex]
The 99% CI for the true proportion of voters who prefer the Republican candidate is (0.3658, 0.6001). This means that we are 99% sure that the true population proportion of all voters who prefer the Republican candidate is (0.3658, 0.6001).
b. If a candidate needs a simple majority of the votes to win the election, can the Republican candidate be confident of victory? Justify your response with an appropriate statistical argument.
The upper bound of the confidence interval is above 0.5 = 50%, which meas that the candidate can be confidence of victory.
Silicone implant augmentation rhinoplasty is used to correct congenital nose deformities. The success of the procedure depends on various biomechanical properties of the human nasal periosteum and fascia. An article reported that for a sample of 10 (newly deceased) adults, the mean failure strain (%) was 24.0, and the standard deviation was 3.2.
Required:
a. Assuming a normal distribution for failure strain, estimate true average strain in a way that converys information about precision and reliability.
b. Predict the strain for a single adult in a way that conveys information about precision and reliability. How does the prediction compare to the estimate calculated in part (a)?
Answers
Solution :
Given information :
A sample of n = 10 adults
The mean failure was 24 and the standard deviation was 3.2
a). The formula to calculate the 95% confidence interval is given by :
[tex]$\overline x \pm t_{\alpha/2,-1} \times \frac{s}{\sqrt n}$[/tex]
Here, [tex]$t_{\alpha/2,n-1} = t_{0.05/2,10-1}$[/tex]
= 2.145
Substitute the values
[tex]$24 \pm 2.145 \times \frac{3.2}{\sqrt {10}}$[/tex]
(26.17, 21.83)
When the [tex]\text{sampling of the same size}[/tex] is repeated from the [tex]\text{population}[/tex] [tex]n[/tex] infinite number of [tex]\text{times}[/tex], and the [tex]\text{confidence intervals}[/tex] are constructed, then [tex]95\%[/tex] of them contains the [tex]\text{true value of the population mean}[/tex], μ in between [tex](26.17, 21.83)[/tex]
b). The formula to calculate 95% prediction interval is given by :
[tex]$\overline x \pm t_{\alpha/2,-1} \times s \sqrt{1+\frac{1}{n}}$[/tex]
[tex]$24 \pm 2.145 \times 3.2 \sqrt{1+\frac{1}{10}}$[/tex]
(31.13, 16.87)
Find the value of x.
Answers
the tic marks show that all sides are congruent, same with the angles. 60+60+60=180 also.
Lesson 1 Skills Practice
Lines For Exercises 1-12, use the figure at the right. In that figure, line m is parallel.
Classify each pair of angles as alternate interior, alternate exterior, or corresponding.
Pictures Below.
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9514 1404 393
Answer:
alternate interior: (2, 4), (3, 5)alternate exterior: (1, 7), (43°, 6)corresponding: (1, 5), (2, 6), (3, 7), alternate interior: (2, 4), (3, 5)corresponding: (1, 5), (2, 6), (3, 7), (43°, 4)4)
Step-by-step explanation:
In this geometry, "corresponding" angles are in the same direction from the point of intersection of the transversal with the parallel line.
"Alternate" refers to angles on opposite sides of the transversal. "Interior" and "exterior" refer to angles between and outside of the parallel lines, respectively.
Here, we list all angle pairs in each classification, so you can answer questions 1-12 based on this list.
alternate interior: (2, 4), (3, 5)
alternate exterior: (1, 7), (43°, 6)
corresponding: (1, 5), (2, 6), (3, 7), (43°, 4)
__
Additional classifications are also used:
consecutive (same-side) interior: (2, 5), (3, 4)
consecutive (same-side) exterior: (1, 6), (43°, 7)
vertical: (1, 3), (2, 43°), (4, 6), (5, 7)
linear pairs: (1, 2), (1, 43°), (2, 3), (3, 43°), (4, 5), (4, 7), (5, 6), (6, 7)
solve for x please help (show ur work)
Answers
Answer:
x = -3
Step-by-step explanation:
12 -4x-5x = 39
Combine like terms
12 - 9x = 39
Subtract 12 from each side
12-9x-12 = 39-12
-9x = 27
Divide by -9
-9x/-9 = 27/-9
x = -3
Answer:
x = -3
Step-by-step explanation:
12 - 4x - 5x = 39
Combine like terms
12 - 9x = 39
Subtract 12 from both sides
12 - 12 - 9x = 39 - 12
-9x = 27
Divide both sides by -9
-9x/-9 = 27/-9
x = -3
Mr Makgato sells his car for R42 000.00. The total commission is 7.2% of the selling price of which the broker receives 2 thirds and the salesperson receives the rest. How much does the broker receive?
Answers
Answer:
2016
Step-by-step explanation:
using USA dollars:
$42000 x .072 (7.2%) = 3024 total commission
3024 x 2/3 = 2016 brokers amount
Yooooo HELPPP
with this question plz
Answers
Answer:
Step-by-step explanation:
(x-2)(x+4)=x^2+4x-2x-8=0=> x =2, x=0
Answer:
A
Step-by-step explanation:
I need help ASAP please please please
Answers
Answer:
n=39/5
Step-by-step explanation:
24=5(n-3)
24=5n-15
-5n= -15-24
-5n=39
n= 39/5
A solid is formed by rotating the region bounded by y = x − x^2 and y = 0 about the line x = 2 . Use the shell method to find the volume of the solid.
Answers
Answer:
The volume of the resulting solid is π/2 cubic units.
Step-by-step explanation:
Please refer to the diagram below.
The shell method is given by:
[tex]\displaystyle V = 2\pi \int _a ^b r(x) h(x)\, dx[/tex]
Where the representative rectangle is parallel to the axis of revolution, r(x) is the distance from the axis of revolution to the center of the rectangle, and h(x) is the height of the rectangle.
From the diagram, we can see that r(x) = (2 - x) and that h(x) is simply y. The limits of integration are from a = 0 to b = 1. Therefore:
[tex]\displaystyle V = 2\pi \int_0^1\underbrace{\left(2-x\right)}_{r(x)}\underbrace{\left(x - x^2\right)}_{h(x)}\, dx[/tex]
Evaluate:
[tex]\displaystyle \begin{aligned} V&= 2\pi \int_0 ^1 \left(2x-2x^2-x^2+x^3\right) \, dx\\ \\ &= 2\pi\int _0^1 x^3 -3x^2 + 2x \, dx \\ \\ &= 2\pi\left(\frac{x^4}{4} - x^3 + x^2 \Bigg|_0^1\right) \\ \\ &= 2\pi \left(\frac{1}{4} - 1 + 1 \right) \\ \\ &= \frac{\pi}{2}\end{aligned}[/tex]
The volume of the resulting solid is π/2 cubic units.
Answer:
pi/2
Step-by-step explanation:
I always like to draw an illustration for these problems.
For shells method think volume of cylinder=2pi×r×h
Integrate(2pi(2-x)(x-x^2) ,x=0...1)
Multiply
Integrate(2pi(2x-2x^2-x^2+x^3 ,x=0...1)
Combine like terms
Integrate(2pi(2x-3x^2+x^3) ,x=0...1)
Begin to evaluate
2pi(2x^2/2-3x^3/3+x^4/4) ,x=0...1
2pi(x^2-x^3+x^4/4), x=0...1
2pi(1-1+1/4)
2pi/4
pi/2
For an avid bird watcher, the probability of spotting a California Condor while birdwatching in the Grand Canyon area is 0.3. The probability of being able to take a clear picture of the bird suppose one is able to spot it is 0.8. What is the probability that the bird watcher is able to take a clear picture of a California Condor
Answers
Answer:
the probability of taking a clear picture of a California candor is .24
The expression y + y + 2y is equivalent to ??
because ??
Answers
Answer:
4y
They would have the same value if a number was substituted for y
Step-by-step explanation:
y+y+2y =
Combine like terms
4y
These are all like terms
They would have the same value if a number was substituted for y
Let y = 5
5+5+2(5) = 5+5+10 = 20
4(5) =20
Which of the following is a geometric sequence? a. 5,-25,125,-625 b.2,4,16,48 c. 13,16,19,22 d. 100,50,0,-50
Answers
Answer:
a
Step-by-step explanation:
B isn't a geometric sequence as it's last term doesn't follow the rule
C is an arithmetic sequence
D is an arithmetic sequence too
Desde cierto paradero se transportan 300 pasajeros en
4 microbuses. ¿Cuántos micros se deben aumentar para
que por cada 3 micros se transporten 90 pasajeros?
Answers
Se necesitan 10 micros si queremos que cada 3 micros transporten 90 pasajeros.
En principio, sabemos que 300 pasajeros pueden transportarse en 4 microbuses.
Entonces, el numero de pasajeros que va por cada micro será el cociente entre el numero de pasajeros y el numero de micros:
N = 300/4 = 75
Queremos responder:
¿Cuántos micros se deben aumentar para que por cada 3 micros se transporten 90 pasajeros?
Definamos X como el numero de grupos de 3 micros que tendriamos en esta situación.
Entonces 300 sobre X, debe ser igual a 90 (el numero de pasajeros que va en cada grupo de 3 micros)
300/X = 90
300 = 90*X
300/90 = X = 3.33...
Notar que el número total de micros sera 3 veces X:
3*X = 3*3.33.... = 10
Se necesitan 10 micros.
Si queres leer más sobre el tema, podes ver.
https://brainly.com/question/23854869
look below for the image
Answers
Answer:
135.7 yd²
Step-by-step explanation:
Surface area of the cone,
πr²+πrl
= π×3²+π×11.4×3
= 43.2π
= 135.7 yd² (rounded to the nearest tenth)
Please help me with 9 I really need it
Answers
Answer:
605 boys.
Step-by-step explanation:
5:7 means 5 parts consists of boys and 7 parts consist of girls.
Since 7 parts = 847, 1 part = 121 and 5 parts = 605
Hence there are 605 boys.
Hope you have a nice day :)
Find the missing side round to the nearest tenth
Answers
======================================================
Work Shown:
sin(angle) = opposite/hypotenuse
sin(29) = x/24
24*sin(29) = x
x = 24*sin(29) ..... exact value
x = 11.635430885912 .... approximate value
x = 11.6
To get the approximate value, you'll need a calculator. Make sure the calculator is in degree mode.
8.113 as a fraction PLEASE HELPP
Answers
Answer:
8 113/1000(as a mixed number) 8113/1000(as an improper fraction)
Step-by-step explanation:
1. Convert 0.113 to a fraction...113/1000
2. As there is no further simplification needed, add 8 to 113/1000....8 113/1000
3. To convert 8 113/1000 from a mixed number to an improper fraction, multiply 8 (the whole number) and 1,000(the denominator)...8,000. Then add 113 (the numerator) to 8,000...8113. After that, you put 8113 over the denominator of the previous mixed number, getting 8113/1000 as the improper fraction.
A group of hens lays 69 eggs in a single day. On one particular day, there were 7 brown eggs and 62 white eggs. If four eggs are selected at random, without replacement, what is the probability that all four are brown?
Answers
Answer:
The probability will 4.32%.
The probability that all four are brown is 35/8,64,501.
Given that, A group of hens lays 69 eggs in a single day. On one particular day, there were 7 brown eggs and 62 white eggs.
What is the probability without replacement?Probability without replacement means once we draw an item, then we do not replace it back to the sample space before drawing a second item. In other words, an item cannot be drawn more than once.
If four eggs are selected at random, without replacement, the probability that all four are brown is 7/69 × 6/68 × 5/67 × 4/66
= 7/69 × 3/34 × 5/67 × 2/33
=7/23 × 1/17 × 5/67 × 1/33
=35/8,64,501
Therefore, the probability that all four are brown is 35/8,64,501.
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Suppose you choose a marble from a bag containing 4 red marbles, 2 white marbles, and 3 blue marbles. You return the first marble to the bag and then choose again. Find P(red then blue).
Answers
Answer:
4/27
Step-by-step explanation:
total number of marbles=9
probability of red=4/9
since you returned the first marble, the total number of marbles remains the same
prob(Blue)=(3/9)=1/3
P(red then blue)=(4/9)*(1/3)
=4/27
Susan randomly selected a sample of plants to determine the average height of the total 35 plants in her garden. She measured the heights (in inches) of 12 randomly selected plants and recorded the data:
1.0, 1.4, 1.8, 2.0, 2.5, 3.5, 4.2, 4.5, 4.8, 5.0, 5.3, 6.0
What is the sample mean of the heights of the plants in Susan's garden?
Answers
Answer:
3.5 inches
Step-by-step explanation:
Sample mean basically means that we need to find the average of the samples.
So the formula for finding average is
Number of observations/ Number of Occurrences
So when we add the values together we get
42.
So there are 12 numbers
So, 42/12 =
3.5 inches
The sample mean of the heights of the plants in Susan's garden is
3.5 inches.
Here,
Susan randomly selected a sample of plants to determine the average height of the total 35 plants in her garden.
She measured the heights (in inches) of 12 randomly selected plants and recorded the data:
1.0, 1.4, 1.8, 2.0, 2.5, 3.5, 4.2, 4.5, 4.8, 5.0, 5.3, 6.0
We have to find the sample mean of the heights of the plants in Susan's garden.
What is Average?
Average value in a set of given numbers is the middle value, calculate as dividing the total of all values by the number of values.
Now,
The recorded data is;
1.0, 1.4, 1.8, 2.0, 2.5, 3.5, 4.2, 4.5, 4.8, 5.0, 5.3, 6.0
To find the sample mean of the heights of the plants in Susan's garden we have to find the average of the recorded data.
Formula for average = [tex]\frac{sum of number of observation}{ number of occurrence}[/tex]
Hence, Average = [tex]\frac{1.0+ 1.4+1.8+2.0+ 2.5+3.5+4.2+4.5+ 4.8+ 5.0+ 5.3+ 6.0}{12} = \frac{42}{12} = 3.5[/tex]
Therefore, The sample mean of the heights of the plants in Susan's garden is 3.5 inches.
Learn more about the average visit:
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A line passes through the point (-2,4) and has a slope of 7. Write an equation for this line
Answers
Answer: y = 7x + 18
Step-by-step explanation:
y = mx + b, (-2,4), m = 7
4 = 7(-2) + b
4 = -14 + b
b = 18
y = 7x + 18
Describe the following sequence using an algebraic expression as a rule 0; 2,4; 6
Answers
Answer:
Step-by-step explanation:
I assume the sequence is 0, 2, 4, 6
nth term = 2(n-1)
PLSSS HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
Answers
Answer:
I believe its EG and NE but i might be wrong
Step-by-step explanation:
1. (02.01)
Solve -4(x + 10) - 6 = -3(x - 2). (1 point)
-40
-46
-52
52
Answers
Answer:
-52
Step-by-step explanation:
-4(x + 10) - 6 = -3(x - 2)
Distribute the left side to get:
(-4x + -40) - 6
Now distribute the right side to get:
-3x + 6
Arrange the equation as the following:
-4x - 40 - 6 = -3x + 6
Add the like terms on each side:
-4x - 46 = -3x + 6
Do the inverse operation of each term:
-x = 52
Now we need to get x to become a positive, so we just divide -x by -1 to get x.
And 52/-1 to get our final answer of -52.
Answer: -52
Step-by-step explanation:
-4(x + 10) - 6 = -3(x - 2)
Distribute the left side to get:
(-4x + -40) - 6
Now distribute the right side to get:
-3x + 6
Arrange the equation as the following:
-4x - 40 - 6 = -3x + 6
Add the like terms on each side:
-4x - 46 = -3x + 6
Do the inverse operation of each term:
-x = 52
Now we need to get x to become a positive, so we just divide -x by -1 to get x.
And 52/-1 to get our final answer of -52.
II. Round to the nearest hundred.
11. 582
12. 1,234
13. 640
14. 770
15. 1,104 can you please tell what the answer?
Answers
Answer:
582-600
1,234-1,200
640-600
770-800
1,104-1,100
у
х
9
3
Find the value of y.
Answers
9514 1404 393
Answer:
(d) 6√3
Step-by-step explanation:
There are several ways to work multiple-choice problems. One of the simplest is to choose the only answer that makes any sense. Here, that is 6√3.
y is the hypotenuse of the medium-sized right triangle, so will be longer than that triangle's longest leg. y > 9
The only answer choice that meets this requirement is ...
y = 6√3
__
In this geometry, all of the right triangles are similar. This means corresponding sides have the same ratio. For y, we're interested in the ratio of long leg to hypotenuse.
long leg/hypotenuse = y/(9+3) = 9/y
y² = 9(9+3) = 9·4·3
y = 3·2·√3 . . . . . . take the square root
y = 6√3
__
Additional comments
You may notice that y is the root of the product of the longer hypotenuse segment (9) and the whole hypotenuse (9+3 = 12). We can say that y is the "geometric mean" of these segment lengths. Similarly (pun only partially intended), x will be the root of the product of the short segment (3) and the whole hypotenuse (12)
x = √(3·12) = 6
This is another "geometric mean" relation.
Further, the altitude will be the geometric mean of the two segments of the hypotenuse:
h = √(9·3) = 3√3
A way to summarize all of these relations is to say that the legs of the right triangle that are not the hypotenuse are equal to the geometric mean of the segments of the hypotenuse that the leg intercepts.
x = √(3·12)
y = √(9·12)
h = √(3·9)
Can anyone please help me out?
