Answer:
The expected value of X, E(X), for the given probability distribution is 1.2
Step-by-step explanation:
Mathematical hope (also known as hope, expected value, population means or simply means) expresses the average value of a random phenomenon and is denoted as E(x).
Hope is the sum of the product of the probability of each event and the value of that event. That is, it is the sum of the probability of each possible event multiplied by the frequency of said process, this indicates that if you have a discrete quantitative variable X with "n" possible events x₁, x₂, x₃... xₙ and probabilities P (X = xi) = Pi the mathematical expectation is:
E(x)=x₁*P₁ + x₂*P₂ + x₃*P₃ + ... + xₙ*Pₙ
In this case:
E(x)=x₁*P₁ + x₂*P₂ + x₃*P₃ + x₄*P₄
Being:
x₁: 0 P₁: 0.5x₂: 1P₂:0.1 x₃:2P₃:0.1 x₄: 3P₄: 0.3and replacing:
E(x)= 0* 0.5 + 1* 0.1 + 2*0.1 + 3*0.3
you get:
E(x)= 1.2
The expected value of X, E(X), for the given probability distribution is 1.2
A cohort study was conducted to examine the relationship between smoking and risk of lung cancer. Among 4000 smokers, 800 were eventually diagnosed with lung cancer and among 6000 non-smokers, 500 were eventually diagnosed with lung cancer. (Use this information to answer questions below)What was the relative risk of being diagnosed with lung cancer in this study?a. 0.08b. 0.13c. 0.20d. 0.40e. 2.40
Answer:
2.4
Step-by-step explanation:
Suppose that computer literacy among people ages 40 and older is being studied and that the accompanying tables describes the probability distribution for four randomly selected people, where x is the number that are computer literate. Is it unusual (using P(x) less than 0.05) to find four computer literates among four randomly selected people?
Answer:
Step-by-step explanation:
The complete question is given thus:
Suppose that computer literacy among people ages 40 and older is being studied and that the accompanying tables describes the probability distribution for four randomly selected people, where x is the number that are computer literate. Is it unusual to find four computer literates among four randomly selected people?
x P(x)
0 0.16
1 0.25
2 0.36
3 0.15
4 0.08
Yes NoANSWER:
The odds that this will occur according to the chart are 0.08, or 8%, so although this is unlikely, it's not terribly unusual.
⇒ NO
So from the following we can say it is not unusual to find four (4) computer literates among four randomly selected people.
ok, so P(1) + P(2) + P(3) + P(4) + P(0) = 0.16+0.25+0.36+0.15+0.08 = 1
Whereas the chance of finding four (4) out of four (4) computer iteration is low when compared to other factors.
cheers i hope this helped !!
The hypotheses relating to the discoveries of radium and Neptune may be classified as empirical hypotheses.
a) true
b) false
Answer:
a) true
Step-by-step explanation:
Empirical hypothesis is the type of hypothesis used to try and explain a phenomenon which leads to a theory been developed and put to the test, using observation and experiment.
Radium was discovered due to a discrepancy in pitchblende's radiation. It was noted by the Curies that Polonium alone could not suffice for that amount of radiation, leading to the theory that another element could be present. After further testing, Radium was discovered as the culprit element.
Also, the presence pf another planet, later discovered to be Neptune was theorized to explain the phenomenon that could cause the irregularities in the motion pattern of the planet Uranus. After much experimentation, observations and calculations, Neptune was discovered.
Solve
x2+ 4x = 4 for x by completing the square.
Answer:
x = -2 +/- √8 or 0.828.... and -4.828....
Step-by-step explanation:
x² + 4x + 4 = 4 + 4
(x + 2)² = 8
x + 2 = +/-√8
x = -2 +/- √8
translation to an equation and solve. Let x be the unknown number. 120% of what number is 60? Type an integer or a decimal.
Answer:
72
Step-by-step explanation:
120% × 60 =
(120 ÷ 100) × 60 =
(120 × 60) ÷ 100 =
7,200 ÷ 100 =
hopefully this helped
What is the slope of the graph ? Leave your answer as a reduced fraction .
In a polynomial do you identify how many terms are in a problem before or after you solve it?
Answer:
All you have to do to identify the number of terms in a polynomial is to count the number of separate parts in the polynomial separated by a plus or minus (terms)
Step-by-step explanation:
A trapezoid has sides of length 5 millimeters, 2 millimeters, 5 millimeters, and 6 millimeters.
What is the perimeter?
millimeters
Answer:
18 millimeters
Step-by-step explanation:
The perimeter of any shape is the sum of the sides. A trapezoid has four sides, so the perimeter is found by adding the four side lengths together.
The trapezoid in this problem has side lengths of 5 mm, 2 mm, 5 mm, and 6 mm.
Add the sides together.
5 mm + 2 mm + 5 mm + 6 mm
7 mm + 5 mm + 6mm
12 mm + 6 mm
18 mm
The perimeter of the trapezoid is 18 millimeters.
Solve F(x) for the given domain.
F(x) = x² + 3x - 2
F(3)=____
a. 13
b. 16
C. 40
Answer:
B. 16
Step-by-step explanation:
F(3) means we must plug the number "3" into the equation for each x.
(3)^2 + 3(3) -2
9 + 9 - 2
16
Answer:
16
Step-by-step explanation:
F(x) = x² + 3x - 2
Let x=3
F(3)= 3^2 +3*3 -2
= 9+9-2
= 18-2
=16
Use the confidence interval to find the margin of error and the sample mean. (1.71, 2.05)
Answer:
Margin of error = 0.17Sample mean = 1.88Step-by-step explanation:
Given:
Sample 1.71 , 2.05
Find:
Margin of error
Sample mean
Computation:
1. Margin of error = (2.05 - 1.71) / 2
Margin of error = 0.34 / 2
Margin of error = 0.17
2. Sample mean = (2.05 + 1.71) / 2
Sample mean = 3.76 / 2
Sample mean = 1.88
What is 72x32 Please help.
Answer:
72
32 x
________
144
2160 +
________
2304
Step-by-step explanation:
Larry and Donna bought a sofa at the sale price of $1,536. The original price of the sofa was $1,920.
Answer: $384
Step-by-step explanation:
1000- 1000=0
900-500=400
20-36=-16
400+-16=384
The time for service call follows a uniform distribution over the interval 20 to 60 minutes.
1. What is the probability that the service call takes longer than 30 minutes?
2. What is the interquartile range?
3. What is the 90th percentile?
Answer:
(1) 0.75
(2) 30
(3) 56
Step-by-step explanation:
Let X represent the time for service call.
It is provided that: [tex]X\sim Uni(20, 60)[/tex]
The probability density function of X is:
[tex]f_{X}(x)=\frac{1}{b-a};\ a<X<b[/tex]
(1)
Compute the probability that the service call takes longer than 30 minutes as follows:
[tex]P(X>30)=\int\limits^{60}_{30} {\frac{1}{60-20}} \, dx[/tex]
[tex]=\frac{1}{40}\times |x|^{60}_{30}\\\\=\frac{60-30}{40}\\\\=\frac{3}{4}\\\\=0.75[/tex]
Thus, the probability that the service call takes longer than 30 minutes is 0.75.
(2)
The Inter quartile range is the difference between the 75th and 25th percentile.
From part (1), we know that P (X > 30) = 0.75.
⇒ 1 - P (X > 30) = 0.75
⇒ P (X < 30) = 0.25
The 25th percentile is 30.
Compute the 75th percentile as follows:
[tex]P(X<x)=0.75\\\\\int\limits^{x}_{20} {\frac{1}{60-20}} \, dx=0.75\\\\\frac{1}{40}\times |x|^{x}_{20}=0.75\\\\x-20=40\times 0.75\\\\x=30+20\\\\x=50[/tex]
The 75th percentile is 50.
Then the inter quartile range is:
[tex]IQR=P_{75}-P_{25}[/tex]
[tex]=50-20\\=30[/tex]
Thus, the inter quartile range is 30.
(3)
Compute the 90th percentile as follows:
[tex]P(X<x)=0.90\\\\\int\limits^{x}_{20} {\frac{1}{60-20}} \, dx=0.90\\\\\frac{1}{40}\times |x|^{x}_{20}=0.90\\\\x-20=40\times 0.90\\\\x=36+20\\\\x=56[/tex]
The 90th percentile is 56.
What is the coefficient of determination for two variables that have perfect positive linear correlation or perfect negative linear correlation? Interpret your answer.
Answer:
r^2 = 1
Step-by-step explanation:
The computation of the coefficient of determination for the two variables is shown below:
here the perfect positive linear correlation is r = 1
And, the negative linear correlation is r = -1
Based on this, the coefficient of determination is equivalent to the linear correlation coefficient square
[tex]r^2 = (\pm)^2 \\\\ = 1[/tex]
This above describes that variation that lies between the variables as explained by the linear regression line
The coefficient of determination for two variables that have perfect positive linear correlation or perfect negative linear correlation is denoted by; r² = (±1)² = 1
The mathematical computation of the coefficient of determination for two variables that have perfect positive linear correlation can be in two forms and is as follows;
The perfect positive linear correlation is denoted, r = 1The negative linear correlation is denoted, r = -1In lieu of this, the coefficient of determination is equivalent to the square of linear correlation coefficient.
r² = (±1)²r² = 1The computation above describes that variation that lies between the variables as explained by the linear regression line.
Read more:
https://brainly.com/question/20038665
A carpenter needs to cut a 5-foot, 8-inch piece of wood form an 8-foot board to make a repair to a door. How many inches of wood will he have left after he makes the cut and repairs the door
Answer:
The left over wood in foot is 2.34 foot
or 2 foot 4 inch
Step-by-step explanation:
This problem desires to test our unit conversion skills
Step one: let us work with foot and convert inches to foot.
The total wood is 8 foot, and we are expected to subtract 5 foot 8 inches from it.
converting 8 inches to foot we have
1 inch -----0.0833333 foot
8 inch-----x foot
cross multiplying we have
x= 8*0.0833333
x= 0.66 foot
Hence the total number of wood to be subtracted in foot is 5.66 foot
i.e 8-5.66= 2.34 foot
The left over wood in foot is 2.34 foot
or 2 foot 4 inch
Show that 3 · 4^n + 51 is divisible by 3 and 9 for all positive integers n.
Answer:
Step-by-step explanation:
Hello, please consider the following.
[tex]3\cdot 4^n+51=3\cdot 4^n+3\cdot 17=3(4^n+17)[/tex]
So this is divisible by 3.
Now, to prove that this is divisible by 9 = 3*3 we need to prove that
[tex]4^n+17[/tex] is divisible by 3. We will prove it by induction.
Step 1 - for n = 1
4+17=21= 3*7 this is true
Step 2 - we assume this is true for k so [tex]4^k+17[/tex] is divisible by 3
and we check what happens for k+1
[tex]4^{k+1}+17=4\cdot 4^k+17=3\cdot 4^k + 4^k+17[/tex]
[tex]3\cdot 4^k[/tex] is divisible by 3 and
[tex]4^k+17[/tex] is divisible by 3, by induction hypothesis
So, the sum is divisible by 3.
Step 3 - Conclusion
We just prove that [tex]4^n+17[/tex] is divisible by 3 for all positive integers n.
Thanks
A first number plus twice a second number is 4. Twice the first number plus the second totals 17. Find the numbers
Answer:
10; -3
Step-by-step explanation:
Let's represent the first number with x, and the second number with y. Now let's write these two equations to find the numbers.
x + 2y = 4
2x + y = 17
We can solve using the substitution method:
x = 4 - 2y
2x + y = 17
2 (4 - 2y) + y = 17
8 - 4y + y = 17
-3y = 9
y = -3
Now plug the value of y in to find x:
x + 2y = 4
x + 2(-3) = 4
x + -6 = 4
x = 10
So, the first number is 10, and the second number is -3.
Cheers.
the difference of two number is 28. if one number is 11, find the other number
Answer:
39
Step-by-step explanation:
difference=28
other number=11
so:
11+28=39
39 is your other number
Answer:
Just simply add the given two numbers and you ll get the answer 39 now to check whether its right or wrong subtract 11 from 39 and you ll get 28 which proves that its correct
Step-by-step explanation:
what is a histogram?
Answer:
A histogram is a graph that organizes a group of data points. A histogram graphically summarize the distribution of a univariate data set.
Write each ratio statement as a fraction and reduce to lowest terms if possible:
18 to 24 =
5 to 15 =
14:42 =
15 cents to 18 cents =
The answers are:
18 to 24 = [tex]\frac{18}{24} = \frac{3}{4}[/tex]
5 to 15 = [tex]\frac{5}{15} = \frac{1}{3}[/tex]
14:42 = [tex]\frac{14}{42} = \frac{1}{3}[/tex]
15 cents to 18 cents = [tex]\frac{15}{18} = \frac{5}{6}[/tex]
Explanation:
To write a fraction using a ratio, simply use the first number as the numerator (top number), in this case, the numbers 18, 5, 14, and 15, and the second or biggest number as a denominator (bottom number), in this case, the numbers 24, 15, 42 and 18. This means the fractions are [tex]\frac{18}{24}[/tex], [tex]\frac{5}{15}[/tex], [tex]\frac{14}{42}[/tex] , and [tex]\frac{15}{18}[/tex].
The second step is to reduce or simplify the fractions, which means the numbers in a fraction are divided by the same factor (a number that divides another without a remainder). Additionally, to do this, it is important to reduce the fraction to its minimum.
[tex]\frac{18}{24}[/tex] divide this by 6, which is equivalent to [tex]\frac{3}{4}[/tex]
[tex]\frac{5}{15}[/tex] divide this by 5, which is equivalent to [tex]\frac{1}{3}[/tex]
[tex]\frac{14}{42}[/tex] divide this by 14. which is equivalent to [tex]\frac{1}{3}[/tex]
[tex]\frac{15}{18}[/tex] divide this by 3, which is equivalent to [tex]\frac{5}{6}[/tex]
−(−49) = −49 true or false?
I hope this helps you
false
cause two negative numbers multiple must be positive
(-1).(-49)
+49
The statement is false.
what is integers?An integer is a whole number (not a fractional number) that can be positive, negative, or zero. Examples of integers are: -5, 1, 5, 8, 97, and 3,043. Examples of numbers that are not integers are: -1.43, 1 3/4, 3.14, . 09, and 5,643.1.
RULE 1: The product of a positive integer and a negative integer is negative.
RULE 2: The product of two positive integers is positive.
RULE 3: The product of two negative integers is positive.
Given:
−(−49) = −49
Is we use the properties of integer
(+).(+)= (+)
(-).(-)=(+)
(-).(+)=(-)
(+).(-)= (-)
So, the statement −(−49) = −49 is false because (-).(-)= (+)
Then, −(−49) = +49
Learn more about integers here:
https://brainly.com/question/15276410
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Find the slope of the line (3,14) and (6,10)
Answer:
The slope is
[tex] - \frac{4}{3} [/tex]
Step-by-step explanation:
To find the slope given two points we use the formula
[tex]m = \frac{y2 - y1}{x2 - x1} [/tex]
where
m is the slope
(x1 , y1) and (x2 , y2) are the points
From the question
The points are (3,14) and (6,10)
The slope of the line (3,14) and (6,10) is
[tex]m = \frac{10 - 14}{6 - 3} = \frac{ - 4}{ 3} [/tex]
[tex]m = - \frac{4}{3} [/tex]
Hope this helps you
Solve the equation [tex]\frac{x}{3} -5=15[/tex]
Answer:
The answer is
x = 60Step-by-step explanation:
[tex] \frac{x}{3} - 5 = 15[/tex]Send 5 to the right side of the equation
That's
[tex] \frac{x}{3} = 15 + 5[/tex][tex] \frac{x}{3} = 20[/tex]Multiply both sides of the equation by 3
We have
[tex]3 \times \frac{x}{3} = 20 \times 3[/tex]x = 20 × 3
We have the final answer as
x = 60Hope this helps you
Given that segment AB is tangent to the circle shown in the diagram centered at point C, determine the value of x
Answer:
x= 37Step-by-step explanation:
This problem can be solved by applying Pythagoras theorem, since the segment AB is tangent to the circle(meaning that the point A is at 90 degree to the circle)
According to Pythagoras theorem "It states that the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares on the other two sides".
given (as seen from the diagram)
x, hypotenuse= ?
opposite= 12
adjacent= 35
Applying Pythagoras theorem
[tex]hyp^2= opp^2+adj^2\\\\hpy=\sqrt{opp^2+adj^2}[/tex]
Substituting our given data and solving for hpy we have
[tex]hyp=\sqrt{12^2+35^2} \\\\hyp=\sqrt{144+1225}\\\\hyp=\sqrt{1369}\\\\hyp= 37[/tex]
hence x= 37
Which of the following rewrites shows the correct process for completing the square? A. 4x^2+9x+5=0 rewritten as 4x^2+9x+81/4=-5+81/4 B. 4x^2+12x+7=0 rewritten as x^2+3x+9/4=-7/4+9/4 C. 3x^2-6x-4=0 rewritten as x^2-2x+1=4+1 D. 2x^2-8x-9=0 rewritten as 2x^2-8x+16=9+16
Answer: B
Step-by-step explanation:
ax² + bx + c = 0 is rewritten as x² + (b/a)x + (b/2a)² = -c/a + (b/2a)²
A) 4x² + 9x + 5 = 0 --> x² + (9/4)x + (9/8)² = -5/4 + (9/8)²
= x² + (9/4)x + 81/64 = -5/4 + 81/64
B) 4x² + 12x + 7 = 0 --> x² + (12/4)x + (12/8)² = -7/4 + (12/8)²
= x² + 3x + 9/4 = -7/4 + 9/4 <---- this works!
C) 3x² - 6x - 4 = 0 --> x² + (-6/3)x + (-6/6)² = 4/3 + (-6/6)²
= x² - 2x + 1 = 4/3 + 1
D) 2x² - 8x - 9 = 0 --> x² + (-8/2)x + (-8/4)² = 9/2 + (-8/4)²
= x² - 4x + 4 = 9/2 + 4
Answer:
B
Step-by-step explanation:
its the correct answer :)
A bag contains 4 red, 6 blue, 4 yellow and 2 green marbles. Once a marble is selected, it is not replaced. What is the probability that in 3 successive draws you will get exactly one blue, one red and no green
Answer:
0.0857
Step-by-step explanation:
What we need is, B R -G, successively. We do not add each probability, but multiply them.
P(1st marble is B) = 6 / 16
P(2nd marble is R) = 4 / 15
*your sample space decreases because you took one marble already before, the Blue one
P(3rd marble is not Green) = 12/14
** it's 12 because you took 2 non-Green marbles before
*** it's 14 because you took 2 marbles before
To arrive at the final answer, just multiply all probability.
If $(x + y)^2 = 1$ and $xy = -4$, what is the value of $x^2 + y^2$? Please Help!!
Expanding the first expression gives
[tex](x+y)^2=x^2+2xy+y^2=1[/tex]
Since [tex]xy=-4[/tex], we have
[tex]x^2+2(-4)+y^2=1\implies\boxed{x^2+y^2=9}[/tex]
Which location has the least elevation
Answer:
the Dead Sea has the least elevation.
The region bounded by y = e−x2, y = 0, x = 0, and x = b (b > 0) is revolved about the y-axis. (Round your answers to three decimal places.) (a) Find the volume of the solid generated when b = 2.
Answer:
0.982 * [tex]\pi[/tex] = 3.085 cubic units
Step-by-step explanation:
To find the volume of the solid generated by a region that is bounded by lines where x = 0 , x (b) = 2 we apply the formula given in the attachment below
the required region boundaries are
y = e^-x2 , y = 0 , x = 0, x = b ( b >0)
attached below is a detailed solution of the problem
PLEASE HELP ASAP it is my homework
Answer:
0.4
Step-by-step explanation:
The number of ways to select 3 points out of 5 points:
N1 = 5C3 = (5 x 4 x 3)/(1 x 2 x3) = 10
The number of ways to select 3 points out of 4 points that are already collinear:
N2 = 4C3 = (4 x 3 x 2)/(1 x 2 x 3) = 4
=> The probability of selecting 3 points that are collinear:
P = N2/N1 = 4/10 = 0.4
Good day, Harry!