Answer:
E. 95
Step-by-step explanation:
[tex]\text{Given that:} \\ \\ X \sim U(a,100) \\ \\ fx(x) = \dfrac{1}{100-a} \\ \\ E[X^2] = \int _x f_x (x) \ dx \\ \\ \implies \int^{100}_{a} \dfrac{x^2}{100-a}dx \\ \\ =\dfrac{100^3-a^3}{3(100-a)} \\ \\ =\dfrac{100^2+100a+a^2}{3} \\ \\ E[X^2] = \dfrac{19600}{3}=\dfrac{100^2+100a+a^2}{3} \\ \\\implies a^2 +100a+10000=19600 \\ \\ \implies a^2 +100a -9600 = 0 \\ \\ \implies a = \dfrac{-100 \pm \sqrt{100^2 -4(-9600)} }{2} \\ \\=\dfrac{-100 \pm \sqrt{48400}} {2} \\ \\ = \dfrac{-100 \pm 220}{2} \\= 60 \ OR \ 160[/tex]
[tex]\text{SInce X is a percentage score on an exam }\ P(X \ge 0) = 1 \text{which means } \ a = 60\\ \\Y \sim U (1.25a,100) = U(75,100)\\ \\ f_y(y) = \dfrac{1}{100-75} = \dfrac{1}{25} \\ \\ \text{Let assume the 80th percentile of Y be} \ y_{80} } \\ \\ \\Then; \ P(Y \le y_{80}) =80\% \implies \int^{y_{80}}_{75} \ f_Y (y) \ dy = 0.8 \\ \\ \implies \int^{y_{80}}_{75}\dfrac{1}{25} \ dy = 0.8 \\ \\ \implies \dfrac{y_{80}-75}{25}= 0.8 \\ \\ \implies y_{80} = 95[/tex]
Find anequation of the line containing (3,-4) and having slope -2. If this line
contains the points (2,8) and (5.b), find a and b.
Answer:
A linear equation can be written as:
y = a*x + b
Where a is the slope and b is the y-intercept.
If we want to have a slope equal to -2, then our line will be something like:
y = -2*x + b
Now, we also want this line to pass through the point (3, -4)
This means that when x = 3, we must have y = -4
Then:
-4 = -2*(3) + b
-4 = -6 + b
-4 + 6 = b
2 = b
Then our line is:
y = -2*x + 2
Now, the second part says that:
If this line contains the points (2,8) and (5.b), find a and b.
This is incorrectly written because this line clearly does not contain the point (2, 8), so i guess the actual problem is something like:
If this line contains the points (a,8) and (5.b), find a and b.
If the line contains the point (a, 8), this means that when y = 8, we must have x = a.
Then:
8 = -2*a + 2
8 - 2 = -2*a
6 = -2*a
6/-2 = -3 = a
a = -3
Similar reasoing for the other point, if the line contains the point (5, b), this means that when x = 5, we have y = b.
Then:
b = -2*5 + 2 = -10 + 2
b = -8
Spaulding is the leading maker for basketballs in the US. Spaulding prides itself on the quality that its basketballs have the right amount of bounce when it is taken out of the packaging. They want their product to be ready for use upon opening. The air pressure of a particular ball has a target value of 7.9 PSI. Suppose the basketballs have a normal distribution with a standard deviation of 0.20 PSI. When a shipment of basketballs arrive, the consumer takes a sample of 21 from the shipment and measures their PSI to see if it meets the target value, and finds the mean to be 7.3 PSI. Perform this hypothesis test at the 5% significance level using the critical value approach.
Answer:
0 < 0.05, which means that we reject the null hypothesis, meaning that the air pressure of the balls is different of the target value of 7.9.
Step-by-step explanation:
The air pressure of a particular ball has a target value of 7.9 PSI.
This means that the null hypothesis is:
[tex]H_{0}: \mu = 7.9[/tex]
The alternate hypothesis is:
[tex]H_{a}: \mu \neq 7.9[/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.
The hypothesis tested means that [tex]\mu = 7.9[/tex]
Suppose the basketballs have a normal distribution with a standard deviation of 0.20 PSI.
This means that [tex]\sigma = 0.2[/tex]
When a shipment of basketballs arrive, the consumer takes a sample of 21 from the shipment and measures their PSI to see if it meets the target value, and finds the mean to be 7.3 PSI.
This means that [tex]X = 7.3, n = 21[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{7.3 - 7.9}{\frac{0.2}{\sqrt{21}}}[/tex]
[tex]z = -13.74[/tex]
pvalue:
We are testing that the mean pressure is different than the target value of 7.9, and since the test statistic is negative, the pvalue is 2 multiplied by the pvalue of z = -13.74, which we find looking at the z-table.
[tex]z = -13.74[/tex] has a pvalue of 0.
2*0 = 0
0 < 0.05, which means that we reject the null hypothesis, meaning that the air pressure of the balls is different of the target value of 7.9.
what is 1+1 please help me?
Answer:
2
Step-by-step explanation:
Answer:
Window :D
Step-by-step explanation:
Okay but it's 2 I gotchu bro
Suppose you know that 10% of 250 is 25. How could you use
that information to find 30% of 250?
Answer:
triple the answer
Step-by-step explanation:
.1×250=25
.3×250= 75
25×3=75
help me plz with that
Tennis practice last for 1 hour and 35 minutes
Answer:
Where's the rest of this question??
Which expression is equivalent to -1/3(6x + 15) - 3?
Answer:
6-x=0
Step-by-step explanation:
-2x+12=0(divide by 2)
6-x=0
Answer:
D is the answer
-2x-8
Step-by-step explanation:
I hope this helps! ^^
Pls answer a and b I will give brainliest answer
Answer:
a. True, b. y = (-1/2)x + 8
Step-by-step explanation:
Because the graph is a straight line, that means that the graph is in fact proportional. For the equation, take the form y = mx+b. Plug in the slope, which is -1/2, and the y-intercept, which is 8, which would give you the equation y = (-1/2)x + 8.
Answer:
1) not proportional - not starting from origin
2) (2,8) - i did it in coordinates
have a great day
Mr. Kramer bought his daughter a kitten for her birthday, so now he needs to buy cat food. First, he gets a 20-pound bag of dry cat food. Then, he finds a good deal on 3-ounce cans of wet cat food, so he buys 48 of them. How many pounds of cat food does Mr. Kramer get in all?
Answer: 29 lbs
Step-by-step explanation: If you do 48 times 3 you will get 144 and if you do 144 divided by 16 you will get 9 and if you do 9 plus 20 you will get 29 lbs in total.
The required pounds of cat food Mr. Kramer get in all is 9.
given that,
First, he gets a 20-pound bag of dry cat food.
Then, he finds a good deal on 3-ounce cans of wet cat food,
so he buys 48 of them.
It is to determine how many pounds of cat food Mr. Kramer get in all.
In mathematics, it deals with numbers of operations according to the statements.
In a can, there are 3 ounces of wet cat food.
1 can = 3 ounce
multiplying both sides by 48
48 can = 3 * 48 ounce
48 can = 144 ounce
1 pound = 16 ounce
1/16 pound = 1 ounce
multiplying both sides by 144 on both sides
144 / 16 pound = 144 ounce
9 pound = 144 ounce
Thus, the required pounds of cat food Mr. Kramer gets in all is 9.
Learn more about arithmetic here:
brainly.com/question/14753192
#SPJ2
Select the statement that describes this expression: 8 + fraction 1 over 2 x (6 − 2) − 1. (2 points)
Group of answer choices
8 more than half the difference of 2 and 1, and then subtract 6
Add 8 to half the difference of 6 and 2, then subtract 1
The sum of 8 and fraction 1 over 2 times 6 plus 2 minus 1
1 less than half of 6 plus the sum of 8 and 2
Answer:
B
Step-by-step explanation:
Add 8 to half the difference of 6 and 2, then subtract 1. Therefore, the option B is the correct answer.
What is PEDMAS rule?PEMDAS is an acronym used to mention the order of operations to be followed while solving expressions having multiple operations. PEMDAS stands for P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, and S- Subtraction.
The given expression is 8+ 1/2×(6-2)-1
= 8+1/2×4-1
= 8+2-1
= 10-1
= 9
Therefore, the option B is the correct answer.
Learn more about the PEDMAS rule here:
https://brainly.com/question/24086845.
#SPJ3
Approximately 32800 citizens of a country died in automobile accidents in 2015
Answer:
question is???
Step-by-step explanation:
please help me pleassee
it's a prism that is good question it's a prism ok a prism
Answer:
A prism. A pyramid would look a little different, and flat too.
Hope that helps!
Step-by-step explanation:
Cody's Seafood House purchases
shrimp for $5.00 per pound. If the
shrimp is marked up 65% how much,
will guests pay for 2 pounds of
shrimp ?
Answer:
Try this
Step-by-step explanation:
So what you have to do is turn 65% into a decimal. 65% as a decimal is 0.65.
Then what you want to do is divide 5.00 and 0.65 and see what you get.
pls answer any that you can!!!
Answer:
12, 45, 1.8, -9, 18
Step-by-step explanation:
up up down down left right left right b a start
what is the value of y?
9514 1404 393
Answer:
y = 8√3
Step-by-step explanation:
In the 30°-60°-90° "special" triangle, the ratio of sides lengths is ...
1 : √3 : 2 = 8 : y : hypotenuse
In order for these ratios to be equal, we must have ...
y = 8√3
__
If you want to solve this using your trig skills, you recognize that ...
Tan = Opposite/Adjacent
tan(30°) = 8/y
y = 8/tan(30°) . . . . where tan(30°) = 1/√3
y = 8√3
Thirty eight years ago George was 14. how old is he now
Answer:
I believe you need to add 38 and 14 together to get answer of 52 years old.
Jared bakes 2 apple pies he cuts the 2 pies into pieces each pieces is 1\8 of a pie
So out of the 2 pies there would be 16 pieces
Answer:
there is 16 pieces
Step-by-step explanation:
If the circumference of a circle measures 3/2TT cm, what is the area of the circle in terms of TT?
A. 3/4 tt cm2
B. 9/2 tt cm2
C. 9/4 tt cm2
D. 9/16 tt cm2
Answer:
A = pi 9/16 cm^2
Step-by-step explanation:
The circumference is 3/2 pi
The circumference is given by
C = 2 * pi *r
3/2 pi = 2 * pi *r
Divide each side by 2 *pi
3/2 pi / 2 pi = 2 pi r /2pi
3/4 cm = r
Now we can find the area
A = pi r^2
A = pi ( 3/4) ^2
A = pi 9/16 cm^2
Answer:
d) 9/16π cm²
Step-by-step explanation:
Circumference = 3/2π cm
diameter = 3/2 cm
radius = 3/2 ÷ 2 = 3/4 cm
area = π(3/4)² = 9/16 π cm²
the length of a rectangle is 6 feet longer than its width the perimeter is less than 48 feet write a mathematical expression for the width of the rectangle
The table below shows the different sizes of 15 pepperoni pizzas sold at a restaurant so far today.
Based on this table what is the probibilty that the next peperonni pizza prize sold will be 8 or more pieces
Answer:
2/3
Step-by-step explanation:
0.2 as a fraction (out of 100)
find the value of x
Answer:
x=6,1,5 is your answer look it once
What is 54.77 rounded to the nearest hundredth ?
A store sold 14 more colored shirts than white shirts. The white shirts cost $9.95 and colors cost $10.50. If a total of $310.60 were sold, how many of each type were sold?
9514 1404 393
Answer:
8 white shirts22 colored shirtsStep-by-step explanation:
Let c represent the number of colored shirts sold. Then c-14 is the number of white shirts sold. The total revenue is ...
10.50c +9.95(c -14) = 310.60
20.45c -139.30 = 310.60 . . . . . . simplify
20.45c = 449.90 . . . . . . . . . . add 139.30
c = 22 . . . . . . . . . . . . . . . . . divide by 20.45
c-14 = 8
22 colored shirts and 8 white shirts were sold.
I need help!
Can you help me please!
Answer:
Step-by-step explanation:
If you use the Puythagorean Theorem, you know that 3^2+3.75^2=X^2 (with X being the hypotenuse)
Then, you simplify and add. you should get 23.0625=X^2
After that you √ (square root) both of them and you get 4.80234318=X
Can someone help me? =)
Four boys shared an apple. The amount each boy ate is listed below. Joey ate 1 2 of the apple. Max ate 1 8 of the apple. Chris ate 1 8 of the apple. Kevin ate 1 8 of the apple. How much of the apple did they eat altogether?
In 2020, you purchase a car for $8000. The value of the car depreciates by 4% each year. What will the approximate value of the car be in 2027? *
Answer:
Step-by-step explanation:
what fraction is bigger? 7/10, 1/5, 9/10
Find the slope of the line that passes through (1, 11) and (9, 10).
Simplify your answer and write it as a proper fraction, improper fraction, or integer.
Answer:
i think it would be negative. -1/8