Answers
Answer:
Step-by-step explanation:
[tex]tan^2x+\sqrt{3} tanx=0\\tanx(tanx+\sqrt{3} )=0\\either~tan~x=0=tan~n\pi \\x=n\pi \\where~n~is~an~integer.\\if~x \in[0,2\pi )\\then~x=0,\pi \\or\\tan~x+\sqrt{3} =0\\tan~x=-\sqrt{3}=tan~(\pi-\frac{\pi }{3} ),tan~(2\pi -\frac{\pi }{3} )\\tan~x=tan(\frac{2\pi}{3} ),tan(\frac{5\pi}{3} )\\x=\frac{2\pi }{3},\frac{5\pi }{3}[/tex]
Related Questions
...For each of the following numbers, find the smallest number by which it should be multiplied so as to get a perfect square number. Also find the square root of the square number so obtained.
(i) 252
(ii) 180
(iii) 1008
(iv) 2028
(v) 1458
(vi) 768
Answers
Answer:
BELOW
Step-by-step explanation:
252 : multiply it by 7 to get 1764 and its square root is 42.
180: multiply it by 5 to get 900 and its square root is 30.
1008: multiply it by 7 to get 7056 and its square root is 84.
2028: multiply it by 3 to get 6084 and its square root is 78.
1458: multiply it by 2 to get 2916 and its square root is 54.
768: multiply it by 3 to get 2304 and its square root is 48.
A number should be a perfect square if its square root is a whole number. The square roots should be integers.
HOPE THIS HELPED
What is the image of (-4, -12) after a dilation by a scale factor of centered at the 1/4 origin?
Answers
9514 1404 393
Answer:
(-1, -3)
Step-by-step explanation:
Each coordinate is multiplied by the dilation factor when dilation is centered at the origin.
(1/4)(-4, -12) = (-1, -3) . . . . the image of the given point
The population of a city increased from 23,400 to 27,800 between 2008 and 2012. Find the change of population per year if we assume the change was constant from 2008 to 2012.
Answers
Find the amount of the increase:
27800 - 23400 = 4,400
Find number of years: 2012 - 2008 = 4 years
Divide amount of change by number of years:
4,400 / 4 = 1,100 people per year.
In a survey of 938 U.S. adults, 235 say the phrase "you know" is the most annoying conversational phrase. Let p be the proportion of the population who respond yes. Use the given information to Construct a 90% confidence interval for p.
Answers
Answer:
CI 90% = ( 0.227 ; 0.273)
Step-by-step explanation:
Information from the survey:
sample size n = 938
number of people with yes answer x = 235
proportion of people p = 235/938
p = 0.25 then q = 1 - 0.25 q = 0.75
Confidence Interval 90 % .
CI 90% = ( p ± SE )
CI 90% = ( p ± z(c)*√(p*q)/n)
CI 90 % then significance level is α = 10 % α/2 = 5%
α/2 = 0.05 we find in z-table z (c) = 1.64
√(p*q)/n = √0.25*0.75/938
√(p*q)/n = √0.000199
√(p*q)/n = 0.014
CI 90% = ( p ± z(c)*√(p*q)/n)
CI 90% = ( 0.25 ± 1.64*0.014)
CI 90% = ( 0.25 ± 0.023 )
CI 90% = ( 0.227 ; 0.273)
One angle of an isosceles triangle is 16 what are the other 2 angles
Answers
Answer:
other two angle will be
82
as 82+82+16 = 180'
Which points are also part of this set of equivalent ratios? Select all that apply.
a. (3, 2)
b. (4, 2)
c. (4, 8)
d. (8, 4)
e. (12, 6)
Answers
Answer:
Option b, (4,2)
Option d, (8,4)
Option e, (12,6)
Answered by GAUTHMATH
Answer:
Option b, (4,2)
Option d, (8,4)
Option e, (12,6)
Step-by-step explanation:
the person above me is correct
the question is in the photo. it is asking for 2 answers
Answers
9514 1404 393
Answer:
2nd force: 99.91 lbresultant: 213.97 lbStep-by-step explanation:
In the parallelogram shown, angle B is the supplement of angle DAB:
∠B = 180° -77°37' = 102°23'
Angle ACB is the difference of angles 77°37' and 27°8', so is 50°29'.
Now, we know the angles and one side of triangle ABC. We can use the law of sines to solve for the other two sides.
BC/sin(A) = AB/sin(C)
AD = BC = AB·sin(A)/sin(C) = (169 lb)sin(27°8')/sin(50°29') ≈ 99.91 lb
AC = AB·sin(B)/sin(C) = (169 lb)sin(102°23')/sin(50°29') ≈ 213.97 lb
Charlie's flower bed has a length of 4 feet and a width of four sixths feet. Which of the following is true
1 The area of the flower bed is equal to 6 square feet.
2The area of the flower bed is larger to 6 square feet.
3 The area of the flower bed is equal to 4 square feet
4 The area of the flower bed is smaller than 4 square feet.
Answers
Answer:
Option 4) The area of the flower bed is smaller than 4 square feet.
Step-by-step explanation:
Let’s solve for the area of the flower bed.
Consider that the flower bed is a rectangle.
The area of a recrangle is given by the formula:
A = length x width
The area of the flower bed is:
4 ft x 4/6 ft = 2 2/3 ft^2
2 2/3 ft ^2 < 4 ft^2
Therefore option 4 is the correct answer.
can someone help me pls
Answers
Answer:
D NO IS THE WRITE ANSWER .
Answer:
D)
Step-by-step explanation:
PLEASE I NEED HELP RIGHT NOW
Select the graph that correctly translates ƒ(x) = |x| 4 units in the negative x-direction and 3 units in the positive y-direction.
answers are the pictures
Answers
Answer:
The third graph
Step-by-step explanation:
What the translation is saying is that for each value of f(x) = |x|, the graph is translated 4 units in the negative x direction and 3 units for the positive y direction. Another way to say this is that for each f(x), we can add (-4) (or subtract 4) to its x value and add 3 to its y value.
One way to find which graph works is to take a point, figure out where it should be, and work from there.
One example of this is (-1,1). If x=-1, |x| is 1, so in the original graph, our point is (-1, 1). In our translated graph, we need to subtract 4 from the x component (the first number, which is -1 in this case) and add 3 to the y component (the second number, or 1 in this case). Our new point comes to
(-1-4 , 1+3)
= (-5, 4)
Therefore, one point on the resulting graph is (-5, 4). We can look through each graph and see if it has the point.
Looking at each graph, it is clear that the graph in the bottom left, or the third graph, contains the point.
The equation of the translated function will be f(x) = |x + 4| + 3. Then the correct option is C.
What is an absolute function?The absolute function is also known as the mode function. The value of the absolute function is always positive.
The absolute function is given as
f(x) = | x – h | + k
The function is given below.
f(x) = |x|
Then the function is translated 4 units in the negative x-direction and 3 units in the positive y-direction. Then the vertex will be at (-4, 3). Then the equation of the function will be
f(x) = |x + 4| + 3
Then the graph is given below.
Then the correct option is C.
More about the absolute function link is given below.
https://brainly.com/question/10664936
#SPJ2
A newspaper infographic titled "Social Media Jeoparding Your Job?" summarized data from a survey of 1,815 recruiters and human resource professionals. The infographic indicated that 51% of the people surveyed had reconsidered a job candidate based on his or her social media profile. Assume that the sample is representative of the population of recruiters and human resource professionals in the United States.
(a) Use the given information to estime the proportion of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile using a 95% confidence interval. (Use a table or technology. Round your answers to three decimal places.)
Give an interpretation of the interval in context. We are 95% confident that the mean number of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile falls within this interval. There is a 95% chance that the true proportion of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile falls directly in the middle of this interval. There is a 95% chance that the true proportion of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile falls within this interval. We are 95% confident that the true proportion of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile falls directly in the middle of this interval. We are 95% confident that the true proportion of recruiters and human resource professionals who have reconsidered a job candidate based on his or her social media profile falls within this interval.
(b) Would a 90% confidence interval be wider or narrower than the confidence interval from part(a)?
Answers
Answer:
hihihihihihihiihihihihihi
Step-by-step explanation:
Show why (2×3×7)^4 = 2^4 × 3^4 × 7^4 show work
Answers
[tex] {a}^{m} \times {b}^{m} = ( {ab)}^{m} [/tex]
(2×3×7)⁴=(2×3)⁴×7⁴(2×3×7)⁴=(2×3×7)⁴RHS=LHSplease mark this answer as brainlist
How do you write it in digits
27 million, 200
Answers
Answer:
27,000,200
Step-by-step explanation:
Going by basic math you know a million has six 0's.
So; one million is represented as 1,000,000.
Hence twenty-seven million as 27,000,000.
Using you tens, hundreds and thousands you'll know 200 will fall into the last area.
CHứng minh rằng trong hệ g - phân với 2
Answers
Find the equation of the midline of the function y = 2 sin(1∕4x) – 3.
A) y = –3
B) y = 3
C) y = 2
D) y = 1∕4
Answers
Explanation:
The general sine equation is
y = A*sin(B(x-C)) + D
where the D variable directly determines the midline. In this case, D = -3, so that corresponds to a midline of y = -3
The sine curve oscillates going up and down, passing through this middle horizontal line infinitely many times. See the graph below.
Answer:
A) y = –3
Step-by-step explanation:I took the test
What is the volume of this rectangular pyramid?
_____ cubic millimeters
Answers
Answer:
Step-by-step explanation:
L = 9 mm
W = 9 mm
H = 10 mm
volume = LWH/3 = 9·9·10/3 = 270 mm³
Which shows the correct substitution of the values a, b, and c from the equation -2 = -x + x2 – 4 into the quadratic
formula?
Quadratic formula: x =
-bb2-4ac
2 a
Ox=
-(-1){V - 1)2 - 4(1)(-4)
2(1)
O x=-11/12-46- 1)( - 4)
2(-1)
O x= -13V (1)? - 4( - 1)(-2)
2(-1)
O x=-(-1)+7(-1)2 - 4(1)(-2)
2(1)
Answers
The values of a, b, c are obtained from the given equation, by equation
in the form in which it is equal to 0.
The correct substitution of the values a, b, and c from the equation -2 = -x + x² - 4 is the option;
[tex]\underline{x = \dfrac{-1 \pm \sqrt{1^2 - 4 \cdot (-1) \cdot (-2)} }{2 \cdot (-1)}}[/tex]Which is the method by which the values of a, b, and c are substituted?Given:
The quadratic formula is presented as follows;
[tex]x = \mathbf{ \dfrac{-b \pm \sqrt{b^2 - 4 \cdot a \cdot c} }{2 \cdot a}}[/tex]
The given equation is presented as follows;
-2 = -x + x² - 4
Which gives;
0 = -x + x² - 4 + 2 = -x + x² - 2
-x + x² - 2 = 0
Therefore, we have;
[tex]x = \mathbf{ \dfrac{-1 \pm \sqrt{1^2 - 4 \times (-1) \times (-2)} }{2 \times (-1)}}[/tex]The correct option is therefore;
[tex]x = \dfrac{-1 \pm \sqrt{1^2 - 4 \cdot (-1) \cdot (-2)} }{2 \cdot (-1)}[/tex]Learn more about the quadratic formula here:
https://brainly.com/question/1630251
Simplify: −4(b+6)−2b(1−4b
Answers
Step-by-step explanation:
-4b-24-2b+8b2
8b2-6b-24=0
A contributor for the local newspaper is writing an article for the weekly fitness section. To prepare for the story, she conducts a study to compare the exercise habits of people who exercise in the morning to the exercise habits of people who work out in the afternoon or evening. She selects three different health centers from which to draw her samples. The 57 people she sampled who work out in the morning have a mean of 5.2 hours of exercise each week. The 70 people surveyed who exercise in the afternoon or evening have a mean of 4.5 hours of exercise each week. Assume that the weekly exercise times have a population standard deviation of 0.6 hours for people who exercise in the morning and 0.4 hours for people who exercise in the afternoon or evening. Let Population 1 be people who exercise in the morning and Population 2 be people who exercise in the afternoon or evening.
Step 1 of 2: Construct a 95% confidence interval for the true difference between the mean amounts of time spent exercising each week by people who work out in the morning and those who work out in the afternoon or evening at the three health centers. Round the endpoints of the interval to one decimal place, if necessary.
Answers
Answer:
The 95% confidence interval for the true difference between the mean amounts of time spent exercising each week by people who work out in the morning and those who work out in the afternoon or evening at the three health centers is (0.5, 0.9).
Step-by-step explanation:
Before building the confidence intervals, we need to understand the central limit theorem and subtraction of normal variables.
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.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
In the morning:
Sample of 57, mean of 5.2, standard deviation of 0.6, so:
[tex]\mu_1 = 5.2[/tex]
[tex]s_1 = \frac{0.6}{\sqrt{57}} = 0.0795[/tex]
In the afternoon/evening:
Sample of 70, mean of 4.5, standard deviation of 0.4, so:
[tex]\mu_2 = 4.5[/tex]
[tex]s_2 = \frac{0.2}{\sqrt{70}} = 0.0239[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 5.2 - 4.5 = 0.7[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0795^2 + 0.0239^2} = 0.083[/tex]
Confidence interval:
The confidence interval is:
[tex]\mu \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower bound of the interval is:
[tex]\mu - zs = 0.7 - 1.96*0.083 = 0.5[/tex]
The upper bound of the interval is:
[tex]\mu + zs = 0.7 + 1.96*0.083 = 0.9[/tex]
The 95% confidence interval for the true difference between the mean amounts of time spent exercising each week by people who work out in the morning and those who work out in the afternoon or evening at the three health centers is (0.5, 0.9).
sample of 1800 computer chips revealed that 25% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature claimed that 28% do not fail in the first 1000 hours of their use. Is there sufficient evidence at the 0.02 level to dispute the company's claim
Answers
Answer:
The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.
Step-by-step explanation:
The company's promotional literature claimed that 28% do not fail in the first 1000 hours of their use.
At the null hypothesis, we test that at least 28% do not fail, that is:
[tex]H_0: p \geq 0.28[/tex]
At the alternative hypothesis, we test if the proportion is of less than 28%, that is:
[tex]H_1: p < 0.28[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
0.28 is tested at the null hypothesis:
This means that [tex]\mu = 0.28, \sigma = \sqrt{0.28*0.72}[/tex]
Sample of 1800 computer chips revealed that 25% of the chips do not fail in the first 1000 hours of their use.
This means that [tex]n = 1800, X = 0.25[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.25 - 0.28}{\frac{\sqrt{0.28*0.72}}{\sqrt{1800}}}[/tex]
[tex]z = -2.83[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample proportion below 0.25, which is the p-value of Z = -2.83.
Looking at the z-table, z = -2.83 has a p-value of 0.0023.
The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.
Use the confidence level and sample data to find a confidence interval for estimating the population μ. Round your answer to the same number of decimal places as the sample mean.
Test scores: n = 92, = 90.6, σ = 8.9; 99% confidence
Options:
A.) 88.2 < μ < 93.0
B.) 88.4 < μ < 92.8
C.) 89.1 < μ < 92.1
D.) 88.8 < μ < 92.4
Answers
Answer: Choice A.) 88.2 < μ < 93.0
=============================================================
Explanation:
We have this given info:
n = 92 = sample sizexbar = 90.6 = sample meansigma = 8.9 = population standard deviationC = 99% = confidence levelBecause n > 30 and because we know sigma, this allows us to use the Z distribution (aka standard normal distribution).
At 99% confidence, the z critical value is roughly z = 2.576; use a reference sheet, table, or calculator to determine this.
The lower bound of the confidence interval (L) is roughly
L = xbar - z*sigma/sqrt(n)
L = 90.6 - 2.576*8.9/sqrt(92)
L = 88.209757568781
L = 88.2
The upper bound (U) of this confidence interval is roughly
U = xbar + z*sigma/sqrt(n)
U = 90.6 + 2.576*8.9/sqrt(92)
U = 92.990242431219
U = 93.0
Therefore, the confidence interval in the format (L, U) is approximately (88.2, 93.0)
When converted to L < μ < U format, then we get approximately 88.2 < μ < 93.0 which shows that the final answer is choice A.
We're 99% confident that the population mean mu is somewhere between 88.2 and 93.0
A consumer advocate agency is concerned about reported failures of two brands of MP3 players, which we will label Brand A and Brand B. In a random sample of 197 Brand A players, 33 units failed within 1 year of purchase. Of the 290 Brand B players, 25 units were reported to have failed within the first year following purchase. The agency is interested in the difference between the population proportions, , for the two brands. Using the data from the two brands, what would be the standard error of the estimated difference, Dp = A – B, if it were believed that the two population proportions were, in fact, equal (i.e., )?
Answers
Answer:
The standard error of the estimated difference is of 0.0313.
Step-by-step explanation:
To solve this question, we need to understand the central limit theorem, and subtraction of normal variables.
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.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Brand A:
33 out of 197, so:
[tex]p_A = \frac{33}{197} = 0.1675[/tex]
[tex]s_A = \sqrt{\frac{0.1675*0.8325}{197}} = 0.0266[/tex]
Brand B:
25 out of 290, so:
[tex]p_B = \frac{25}{290} = 0.0862[/tex]
[tex]s_B = \sqrt{\frac{0.0862*0.9138}{290}} = 0.0165[/tex]
What would be the standard error of the estimated difference?
[tex]s = \sqrt{s_A^2+s_B^2} = \sqrt{0.0266^2+0.0165^2} = 0.0313[/tex]
The standard error of the estimated difference is of 0.0313.
Need the answer explained
Answers
Answer:
it's very simple maybe it's in ur book?
The charge of eletricity for the first 20 unit is Rs 80 and Rs 7 per unit from 21 unit to 30 units. If service is Rs 75 find the total charge of 28 units
Answers
28 - 20 = 8 units
8 x 7 = Rs 35
80 + 35 = Rs 115
If (5x+3):(7x+3)=3:4, find the value of x.
Answers
[tex]\\ \sf\longmapsto \dfrac{5x+3}{7x+3}=\dfrac{3}{4}[/tex]
[tex]\\ \sf\longmapsto 4(5x+3)=3(7x+3)[/tex]
[tex]\\ \sf\longmapsto 20x+12=21x+9[/tex]
[tex]\\ \sf\longmapsto 12-9=21x-20x[/tex]
[tex]\\ \sf\longmapsto x=3[/tex]
[tex]\large\rm \longrightarrow \: {\purple{ \frac{(5x + 3)}{(7x + 3)} \: = \: \frac{3}{4} }} \\ [/tex]
⇛ Now , Cross Multiplying
[tex]\large\rm \longrightarrow \: {\blue{ 4 \: (5x + 3) \: = \: 3 \: (7x + 3)}}[/tex]
[tex]\large\rm \longrightarrow \: {\red{ 20x \: + \: 3 \: = \: 21 \: + \: 3}}[/tex]
[tex]\large\rm \longrightarrow \: {\orange{ 12 \: - \: 9 \: = \: 21x \: - \: 20x }}[/tex]
[tex]\large\rm \longrightarrow \:{\green{ 3 \: = \: x}}[/tex]
⇛ Hence , the value of x is 3
21. 13/4 x 42/9 =
O
A. 132/18
B. 64/9
O
C. 77/18
D. 41/6
Worth 2 points
Answers
3. An elevator is moving upward with a speed of 14.3 m/s . Two seconds later, the elevator is still moving upward, but its speed bas been reduced to 3.7 m/s . What is the average acceleration of the clevator during the 2.0 interval?
Answers
By definition of average acceleration,
a (average) = (3.7 m/s - 14.3 m/s) / (2.0 s) = -5.3 m/s²
a motercycle can travel 60 miles per gallon. approximently how many gallons of fuel will the motercycle need to travel 40 km
[1 mile = 1.6km]
a: 0.04
b: 0.08
c: 0.20
d: 0.42
Answers
Answer:
D. 0.42
Step-by-step explanation:
First, convert 40 km to miles by dividing it by 1.6:
40/1.6
= 25
Create a proportion where x is the number of gallons the motorcycle will need to travel 40 km (25 miles):
[tex]\frac{60}{1}[/tex] = [tex]\frac{25}{x}[/tex]
60x = 25
x = 0.4166
Round this to the nearest hundredth:
x = 0.42
So, to travel 40 km, the motorcycle will need 0.42 gallons of fuel.
The correct answer is D. 0.42
Which of the following choices is equivalent to the equation below?
5(2x−1) = 5(5x−14)
A 2x − 1 = 5x − 14
B 5(2x − 1) = 5x − 14
C 2x − 1 = 5
D None of these choices are correct.
Answers
Answer:
2x-1 = 5x-14
Step-by-step explanation:
5(2x−1) = 5(5x−14)
Divide each side by 5
5/5(2x−1) = 5/5(5x−14)
2x-1 = 5x-14
Answer:
A.
Step-by-step explanation:
5(2x−1) = 5(5x−14)
10x - 5 = 25x - 70
65 = 15x
x = 13/3.
Take Option A.
2x - 1 = 5x - 14
3x = 13
x = 13/3 so its this one.
B: 10x - 5 = 5x - 14
5x = -9
x = -9/5 so NOT B.
C. simplifies to x = 3. so NOT C.
s A lottery offers one 800 prize, one 700 Prize, two 800 prizes, and four prizes. One thousand tickets are sold at each. Find the expectation if a person buys two tickets. Assume that the player's ticket is replaced after each draw and that the same ticket can win more than one prize. Round to two decimal places for currency problems.
Answers
The question is incomplete. The complete question is :
A lottery offers one $800 prize, one $700 Prize, two $800 prizes, and four $100 prizes. One thousand tickets are sold at $5 each. Find the expectation if a person buys two tickets. Assume that the player's ticket is replaced after each draw and that the same ticket can win more than one prize. Round to two decimal places for currency problems.
The expected if a person buys two tickets is $__
Answer:
$ -1.52
Step-by-step explanation:
Given :
A lottery offers --
One $800 prize
One $700 prize
Two $800 prize
Four $100 prizes
Let X = net win
X P(X)
795 1/1000
695 1/1000
795 2/1000
95 4/1000
-5 996/1000
[tex]$E(X) = \sum X \ p(X)$[/tex]
[tex]$=795 \times \frac{1}{1000} + 695 \times \frac{1}{1000} + 795 \times \frac{2}{1000} + 95 \times \frac{4}{1000} + (-5) \times \frac{996}{1000}$[/tex]
= 0.795 + 0.695 + 1.59 + 0.38 - 4.98
= $ -1.52
