Answer:
a) the probability of (2 < X < 6) is 0.6247
b) the value of c is 3.878
c) the value of E[ x² ] is 13
Step-by-step explanation:
Given that;
mean μ = 3
variance = 4
standard deviation s = √variance = √4 = 2
(a) Find the probability P(2 < X < 6)
P(2 < X < 6) = p( (x - μ / s ) < z < (x - μ / s ) )
= p( (2 - 3 / 2 ) < z < (6 - 3 / 2 ) )
= p( -0.5 < z < 1.5)
from z-score table, 1.5; z = 0.9332 and -0.5; z = 0.3085
so
P(2 < X < 6) = 0.9332 - 0.3085 = 0.6247
Therefore, the probability of (2 < X < 6) is 0.6247
b) Find the value c such that P(X > c) = 0.33
with p-value = 0.33, the corresponding z -score to the right is 0.439
we know that;
z = x - μ / s
we substitute
0.439 = x - 3 / 2
x - 3 = 2 × 0.439
x - 3 = 0.878
x = 0.878 + 3
x = 3.878
Therefore, the value of c is 3.878
c) Find E[ x² ].
Variance = E[ x² ] - [ mean ]²
E[ x² ] = Variance + [ mean ]²
we substitute
E[ x² ] = 4 + [ 3 ]²
E[ x² ] = 4 + 9
E[ x² ] = 13
Therefore, the value of E[ x² ] is 13
The distribution follows a normal distribution.
[tex]\mathbf{P(2 < x < 6) =0.6247}[/tex]The value of c is 3.878The value of [tex]\mathbf{E(x^2) }[/tex] is 13The given parameters are:
[tex]\mathbf{\mu = 3}[/tex] --- mean
[tex]\mathbf{\sigma^2= 4}[/tex] --- variance
(a) P(2 < x < 6)
Start by calculating the standard deviation
[tex]\mathbf{\sigma = \sqrt{\sigma^2}}[/tex]
This gives
[tex]\mathbf{\sigma = \sqrt{4}}[/tex]
[tex]\mathbf{\sigma =2}[/tex]
Calculate the z-scores for x = 2 and 6
[tex]\mathbf{z = \frac{x - \mu}{\sigma}}[/tex]
So, we have:
[tex]\mathbf{z = \frac{2 - 3}{2} = -0.5}[/tex]
[tex]\mathbf{z = \frac{6 - 3}{2} = 1.5}[/tex]
So, the probability becomes
[tex]\mathbf{P(2 < x < 6) = P(-0.5 < z < 1.5)}[/tex]
Using z table of probabilities, we have:
[tex]\mathbf{P(2 < x < 6) =0.9332 - 0.3085}[/tex]
[tex]\mathbf{P(2 < x < 6) =0.6247}[/tex]
(b) Calculate c if P(X > c) = 0.33
Start by calculating the z-score for p-value = 0.33
From the z table, z = 0.439 when p-value = 0.33
Recall that:
[tex]\mathbf{z = \frac{x - \mu}{\sigma}}[/tex]
So, we have:
[tex]\mathbf{0.439 = \frac{x - 3}{2}}[/tex]
Multiply both sides by 2
[tex]\mathbf{0.878= x - 3}[/tex]
Add 3 to both sides
[tex]\mathbf{3.878= x}[/tex]
Rewrite as:
[tex]\mathbf{x = 3.878}[/tex]
Replace x with c
[tex]\mathbf{c = 3.878}[/tex]
The value of c is 3.878
(c) Calculate E[x²]
The variance of a dataset is:
[tex]\mathbf{\sigma^2 =E(x^2) - \mu^2}[/tex]
Substitute known values
[tex]\mathbf{4 =E(x^2) - 3^2}[/tex]
[tex]\mathbf{4 =E(x^2) - 9}[/tex]
Add 9 to both sides
[tex]\mathbf{13 =E(x^2) }[/tex]
Rewrite as:
[tex]\mathbf{E(x^2) = 13 }[/tex]
Hence, the value of [tex]\mathbf{E(x^2) }[/tex] is 13
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Sukie interviewed 125 employees at her company and discovered that 21 of them planned to take an extended vacation next year. She finds that the proportion of people taking extended vacations nationally is 15%. z equals fraction numerator p with hat on top minus p over denominator square root of begin display style fraction numerator p q over denominator n end fraction end style end root end fraction The z statistic for this data is __________. -0.56 0.45 -0.45 0.56
Answer:
0.56
Step-by-step explanation:
RATIONALE
To make things a little easier, let's first note the denominator
We can now note that
Finally, subbing all in we find
Answer:
0.56
Step-by-step explanation:
Based on a​ survey, assume that ​48% of consumers are comfortable having drones deliver their purchases. Suppose that we want to find the probability that when consumers are randomly​ selected, exactly of them are comfortable with delivery by drones. Identify the values of​ n, x,​ p, and q. The value of n is ______.
Answer:
The value of n is the size of the sample, the number of customers selected.
The value of p is 0.48.
The value of q is 0.52.
Step-by-step explanation:
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
48% of consumers are comfortable having drones deliver their purchases.
This means that [tex]p = 0.48, q = 1 - p = 1 - 0.48 = 0.52[/tex]
The value of n is the size of the sample, the number of customers selected.
)A bag contains 20 marbles of the same size that are blue, green, and red. The probability of picking a blue marble is 20%. The probability of picking a green marble is 50%. Determine the probability of picking a red marble from the bag and then classify the probability of picking a red marble as likely or not likely to occur.
Answer:
If the bag contained 20% of blue marbles and 50% of green marbles than that would mean the bag would contain 30% of red marbles. The probability of picking a red marble from the bag would be considered unlikely.
Step-by-step explanation:
Find the area of the smaller sector.
140°/6 in
1404
Area =
[ ? Jin2
B В
Round your answer to the nearest hundredth.
Answer:
43.96
Step-by-step explanation:
3.14 x 6^2 x 140/360
Danny charges $30 for 3 hours of swimming lessons, Martin charges $38 for 2 hours of swimming lessons. Who offers a better deal?
Answer:
Danny
Step-by-step explanation:
Danny charges less because he only charges $30 for 3 hours of swimming lessons while Martin charges $38 for only 2 hours of swimming lessons.
Find the x- and y-intercepts of the graph of 7x – 10y = 30. State your answers as
whole numbers or as improper fractions in simplest form.
x-intercept:
y-intercept:
Answer:
x-intercept: 7/30
y-intercept: −3
Step-by-step explanation:
Answer:
Step-by-step explanation:
For x-intercept:
Substitute y=0:
7x-10(0)=30
7x=30
x=30/7
For y-intercept:
Substitute x=0:
7(0)-10y=30
-10y=30
y=-30/10
y=-3
Which is an irrational number Square root of 21 3 5/8 2.4141414 or -13
Answer:
i dont know
Step-by-step explanation:
Multiply the sum 5 and 3 and the sum of 8 and 9
Answer:
136
Step-by-step explanation:
Sum of 5 and 3: 8
Sum of 8 and 9: 17
17 * 8 is 136
Answer: The sum of 5 and 3 is 8 and the sum of 8 and 9 is 17.
what is aquifelent to 3 mi
What measurement do you need? For ft it's 15840
Answer:
I do not know
Step-by-step explanation:
I do not know
Please show the work.
1. A wheelchair ramp is 4.2 m long. I rises 0.7 . What is its angle of inclination to the nearest degree?
2. A person flying a kite has released 176 m of string and attached the end to the ground. The string makes an angle of 27 degree with the ground. How high is the kite? How far away is the kite horizontally? Answer to the nearest meter.
Answer:
see explanation
Step-by-step explanation:
(1)
The angle of inclination is the angle between the horizontal and the ramp.
Using the sine ratio in the right triangle formed by the ground and the ramp
let x be the angle of inclination, then
sinx = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{0.7}{4.2}[/tex] , then
x = [tex]sin^{-1}[/tex] ([tex]\frac{0.7}{4.2}[/tex] ) ≈ 10° ( to the nearest degree )
(2)
Again there is a right triangle between the ground and the vertical height of the kite, with hypotenuse being length of string.
let y be the height of the kite and x the horizontal distance, then
sin27° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{y}{176}[/tex] ( multiply both sides by 176 )
176 × sin27° = y , then
y ≈ 80m ( to the nearest metre ) ← height of kite
and
cos27° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{x}{176}[/tex] ( multiply both sides by 176 )
176 × cos27° = x , then
x ≈ 157m ( to the nearest metre ) ← horizontal distance
Step-by-step explanation:
[tex]1)
The angle of inclination is the angle between the horizontal and the ramp.
Using the sine ratio in the right triangle formed by the ground and the ramp
let x be the angle of inclination, then
sinx = \frac{opposite}{hypotenuse}hypotenuseopposite = \frac{0.7}{4.2}4.20.7 , then
x = sin^{-1}sin−1 (\frac{0.7}{4.2}4.20.7 ) ≈ 10° ( to the nearest degree )
(2)
Again there is a right triangle between the ground and the vertical height of the kite, with hypotenuse being length of string.
let y be the height of the kite and x the horizontal distance, then
sin27° = \frac{opposite}{hypotenuse}hypotenuseopposite = \frac{y}{176}176y ( multiply both sides by 176 )
176 × sin27° = y , then
y ≈ 80m ( to the nearest metre ) ← height of kite
and
cos27° = \frac{adjacent}{hypotenuse}hypotenuseadjacent = \frac{x}{176}176x ( multiply both sides by 176 )
176 × cos27° = x , then
x ≈ 157m ( to the nearest metre ) ← horizontal distance
[/tex]
When the following inequality is graphed, what will it look like?
2 > f
Answer:
Step-by-step explanation:
A straw is placed inside a rectangular box that is 10 inches by 8 inches by 2 inches, as
shown. If the straw fits exactly into the box diagonally from the bottom left corner to
the top right back corner, how long is the straw? Leave your answer in simplest
radical form.
The length of the straw placed inside a rectangular box with 10 inches by 8 inches by 2 inches is 2√42 inches.
To find the length of the straw, we can use the Pythagorean theorem. The straw acts as the hypotenuse of a right-angled triangle formed by the three dimensions of the box (10 inches, 8 inches, and 2 inches).
Let the length of the straw be represented by 'l'.
According to the Pythagorean theorem:
[tex]l^2 = 10^2 + 8^2 + 2^2[/tex]
[tex]l^2 = 100 + 64 + 4[/tex]
[tex]l^2 = 168[/tex]
Take square root on both sides:
[tex]l = \sqrt{168}[/tex]
[tex]l = \sqrt{4 \times 42}[/tex]
[tex]l = 2 \times \sqrt{42}[/tex]
So, the length of the straw is 2√42 inches in simplest radical form.
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Complete question:
A straw is placed inside a rectangular box that is 10 inches by 8 inches by 2 inches, as shown. If the straw fits exactly into the box diagonally from the bottom left corner to the top right back corner, how long is the straw? Leave your answer in simplest radical form.
(2x³ - 10x² + 4x - 20) / (x - 5) = ?
Step-by-step explanation:
2x³ - 10x² + 4x - 20
= 2x²(x - 5) + 4(x - 5)
= (2x² + 4)(x - 5).
Hence (2x³ - 10x² + 4x - 20) / (x - 5)
= [(2x² + 4)(x - 5)] / (x - 5) = 2x² + 4.
Answer:
2x²+4
Step-by-step explanation:
2x³-10x²+4x-20
2(x³-5x²+2x-10)
x-5
2(x²×(x-5)+2(x-5)
x-5
2(x-5)×(x²+2)
x-5
2(x²+2)
=2ײ+4
Help and explain
Don’t use for points or I will take it back
Step-by-step explanation:
step 1. x + 51 + 39 + 127 = 360 (1 revolution is 360°)
step 2. x + 90 + 127 = 360
step 3. x + 127 = 270. (subtract 90 on both sides)
step 4. x = 143° (subtract 127 on both sides)
please help will mark you as brainiest
Rimo spends £588 on a plane ticket and $130 on airport tax. Using £1 = $1.34, what percentage of the total cost does Rimo spend on airport tax?
Give your answer rounded to 1 dp.
According to a Pew Research Center study, 14% of Americans have changed their views on a political or social topic in the last year because of something they saw on social media. Let the random variable be the number of people, from a random sample of 60 Americans, who have changed their political or social views in the last year because of social media.
Is the number of these people who have changed their views because of social media a binomial random variable?
A. Yes. All four conditions are met.
B. No. There is not a fixed number of trials.
C. No. The trials cannot reasonably be assumed to be independent.
D. No. The outcomes cannot be described as only "success" and failure"
E. No. The probability of success is not the same for each trial.
Answer:
A. Yes. All four conditions are met.
Step-by-step explanation:
Binomial random variable:
Can only have two outcomes(yes/no questions).
Each trial must be independent, that is, the probability of a success is always the same in a trial.
It's probabilities must be between 0 and 1.
Number of these people who have changed their views because of social media a binomial random variable.
For each people, there are only two possible outcomes. Either they did change, or they did not. For each people, the probability of changing is independent of other people, that is, the probability is the same, so yes, the conditions are met.
The table shows the feeding times of some animals in a zoo. Each feeding session lasts for 20 minutes.
Answer: 12:35 hrs
Step-by-step explanation:
Marlon watches the lions feed in the morning which was at 11:30.
Each feeding session lasts 20 minutes:
= 11:30 + 20
= 11:50 am
Marlon then walks for three quarters of an hour - 45 minutes - before stopping.
= 11:50 + 45
= 12:35 hrs
Which of these systems of equations has one solution?
Answer: B
Step-by-step explanation:
Make a conjecture. Let points A and B stay in the same
position. What would happen to the angle formed if the
vertex of angle AOB was moved from the center to point
C, which lies on the circle?
The measure of angle ACB is
the
measure of angle AOB.
Answer:
✔ less than
Step-by-step explanation:
The measure of angle ACB is less than the measure of the angle AOB.
GIven,
Making the conjecture.
What would happen to the angle formed if the vertex of angle AOB was moved from the center to point C, which lies on the circle is to be justify.
The circle is the locus of a point whose distance from a fixed point is constant i.e center (h, k). The equation of the circle is given by
(x - h)² + (y - k)² = r². where h, k is the coordinate of the circle's center on coordinate plane and r is the circle's radius.
Here, there is a property of pair of lines,
when two lines intersect each other they hold some angle of intersection with each other, when the angle of intersection increases, assuming a point says the point of intercession getting close to the points then angle of the intersection will increase. If the point of intersection gets far away from that point, the angle of the intersection will decrease.
Similarly, in the given problem point O is close to the arc AB than C. Implies Angle ACB is smaller than Angle AOB.
Thus, the measure of angle ACB is less than the measure of the angle AOB.
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write at least 250 word about a way you have used math outside of school. Use your own word
A high school drama department sold 238 tickets for their performance.
• An adult ticket cost $6.75.
• A student ticket cost $3.50.
• The high school drama department collected $1,252.25 in ticket sales.
How many student tickets were sold?
Answer:
358 student
Step-by-step explanation:
3.50×358=1252
Help please!!!!!!!!
Find the missing length indicated.ii
tell me you love me pls i need sum luv i spents alot of time doing this im doing another one but 100 pts
Answer:
I love you and i'm proud of you :)
I need help please help me
Answer:
a. 85 m
b. 96 cm
Step-by-step explanation:
Work for (a.)
95 x 2 = 190. 360 - 190 = 170170 ÷ 2 = 85Final Answer: 85 mWork for (b.)
58 x 2 = 1165568 ÷ 58 = 96 To make sure: 96 x 58 = 5568Final Answer: 96 cmAnyone know the answer
Answer:
S(4) = 2
Step-by-step explanation:
S(n) = n(n - 3) / 2
S(4) = 4(4 - 3) / 2
= 4 x 1 / 2
= 4/2
= 2
Class: How can we graph using slope intercept form?
1/3y=x
Mr. Ferguson's classroom is 30 ft long, 20 ft wide, and 10 ft tall. There are 3 concrete
columns in the room. Each column is 10 ft tall with a radius of 2 ft. What is the
volume of the classroom without the columns?
Rectangular Prism: V = lwh
Cylinder: V = tirah
Type a number only for your answer - no units.
Example 525.89
Answer:
they all went to the stairs
Step-by-step explanation:
67.90 I don't know u tell me
f(x) = -2x²-2x+10, find f(2)
Answer:
f(2) = -2
Step-by-step explanation:
Substitute 2 everywhere you see an x so f(2) = -2([tex]2^{2}[/tex]) - 2(2) + 10 so
f(2) = -2(4) - 4 + 10, so f(2) = -8-4+10, f(2) = -12+10, f(2) = -2
Explain why an archaeological matrix is important in archeology
Answer:
The stratigraphic relationships that are documented as a principal part of the record of the excavation form a fundamental part of the overall site record and underpin the relationships between the site's other recorded individual archaeological components.
Step-by-step explanation:
