Researchers doing a study comparing time spent on social media and time spent on studying randomly sampled 200 students at a major university. They found that students in the sample spent an average of 2.3 hours per day on social media and an average of 1.8 hours per day on studying. If all the students at the university in fact spent 2.2 hours per day on studying, with a standard deviation of 2 hours, the probability of getting a sample average of 1.8 or less is:________.a. 0.5893 b. 0.9977 c. 0.4207 d. 0.0023
Answer:
d. 0.0023
Step-by-step explanation:
Calculation for the probability of getting a sample average of 1.8 or less
Using this formula
z score =(X-mean)/Standard errror
Where,
Standard error =Standard deviation/√(n)
Let plug in the formula
P(Xbar<1.8)=P(Z<(1.8 hours per day -2.2 hours per day)/(2 hours /√(200))
P(Xbar<1.8)=P(Z<-0.4/(2/14.14))
=P(Z<-0.4/0.1414)
=P(Z<-2.83)
Now let find the Z score of P(Z<-2.83) using the z table
P=0.0023
Therefore the probability of getting a sample average of 1.8 or less is:0.0023
I don’t understand this question can you also help me figure it out step by step I would greatly appreciated it
Answer:
If a shape is a square, then it is a quadrilateral
Step-by-step explanation:
Quadrilateral means four sided shape, so automatically, because a square has 4 sides, you know it is a quadrilateral. But not all quadrilaterals are a square, you could have a rectangle which is four sides so you know that this statement is wrong "If a shape is a quadrilateral, then it is a square." Therefore, the answer is "If a shape is a square, then it is a quadrilateral
Let u = 2i + 3j, v=-i, and w = 5i – 6j. What is the magnitude of 2(u - V + w)?
•10.0
•13.4
•17.1
•21.6
Answer:
B. 17.1
Step-by-step explanation:
Edge 2020. Hope this helps.
The magnitude of 2(u-v +w) is √292.
The given vectors are u = 2i + 3j, v=-i, and w = 5i – 6j.
We need to find the value of 2(u-v+w).
How to find the magnitude of vector?The formula to determine the magnitude of a vector (in two-dimensional space) v = (x, y) is: |v| =√(x²+ y²). This formula is derived from the Pythagorean theorem.
Now, 2(2i + 3j-(-i)+5i-6j)
=2(2i+3j+i+5i-6j)
=2(8i-3j)=16i-6j
The magnitude of 16i-6j=√16²+6²=√256+36=√292
Therefore, the magnitude of 2(u-v +w) is √292.
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What is the factored form of the equation 4x^2-11+6=0
Answer:
(4x−3)(x−2)=0
Step-by-step explanation:
Step-by-step explanation:
4x²-11+6=0
4x²-5=0
x²=5
4
x=√5
4
hope it help u
12 students is what percent of 60 students?
Answer:
20%
Step-by-step explanation:
Answer:
20%
Step-by-step explanation:
I believe it is 20% based on what I know.
During November, $83 was spent on travel. In December, $65 was spent on travel. How much was the percent of decrease? Round to the nearest tenth of a percent.
Pls Help
Answer:
Percent decrease is 21.7%
Step-by-step explanation:
The percent decrease is calculated as:
[tex]Decrease\ percentage = \frac{decrease}{Original\ quantity} * 100[/tex]
Given in the question that:
Cost on travel during November = $83
Cost on travel during December = $65
The percent decrease will be calculated by computing decrease(subtracting the cost of December from the cost of November.
[tex]Decrease = Travel\ cost\ in\ November - Travel\ cost\ in\ december\\Decrease = \$83-\$65\\= \$18[/tex]
Now, for percentage decrease
[tex]Percentage\ decrease = \frac{decrease}{Travelling\ cost\ in\ November} * 100\\=\frac{18}{83} * 100\\=21.686..[/tex]
Rounding off to nearest tenth of percent, we get the percentage decrease as 21.7%
Hence,
Percent decrease is 21.7%
f(x) = x2 – 2x +1
Find y-intercept and vertex
Answer:
Your answer is: The x-intercept is [tex](1 , 0)[/tex] and your y-intercept is[tex](0 , 1 )[/tex].
Your vertex is [tex](1 , 0)[/tex]
Step-by-step explanation:
In order to find the y-intercept you had to to find the x-intercept, substitute in 0 for y and solve for x . To find the y-intercept, substitute in 0 for x and solve for y.
In order to find the vertex you had rewrite the equation in vertex form and use this form to find the vertex [tex](h , k)[/tex].
Hope this helped : )
Find answer to picture problem
Answer:
Can you add the picture please???
Step-by-step explanation:
Abdul has bought 30 pounds of dog food. He feeds his dog
2/3 pounds for each meal. For how many meals will the food last?
Answer: I think its 45 days
Step-by-step explanation: hope this helps
Bella went shopping for a new phone. To find the total plus tax, she multiplied the price of the phone by 1.075. What percent tax did she pay?
What conclusions can you draw from the graph?
Answer:
My best conclusion (simply put) is that you had a higher score than the average class.
Step-by-step explanation:
It obvious that the green dots is above the averages of both bars. It would be safe to think that you scored higher than the average of the entire class in both predictions and parabolas.
At a carnival, Tammy bought 9 packs of 17 tickets each. She has used 36 of the tickets so far. How many tickets does she have left?
㏒㏑⊂·_·⊃㏒㏑
Yan has already finished Three-fifths of the 45 math problems he was assigned today. Each math problem took him 1Four-fifths of a minute to complete. If this pace continues, how much more time, to the nearest minute, will the rest of the problems take him to finish?
Answer:
49 Minutes
Step-by-step explanation:
1. 27 = 1 4/5 Minutes per 1 question.
2. Each question takes 108 seconds.
3. By this Logic, we can do 108 seconds x 27 questions to get-
4. 48.6 Minutes
5. And finally we round to the nearest minute so we get 49 minutes in total.
Answer:
32 minutes
Step-by-step explanation:
Yan has already finished Three-fifths of the 45 math problems he was assigned today. Each math problem took him 1Four-fifths of a minute to complete. If this pace continues, how much more time, to the nearest minute, will the rest of the problems take him to finish?
Subtract using the number line. - 1/3-(-1/2)
Answer:
answer is 1/1
Step-by-step explanation:
Jay needs to paint one side of his house. He knows 1 can of paint covers and area of 24 square feet. What is the least amount of paint Jay will need to paint the side of his house?
Answer:
he will need 4 cans to make it 100 %compleate
A 2 yard piece of ribbon costs $10.80. What is the price per inch?
Answer:
0.15
Step-by-step explanation:
2 yards = 72
10.80 / 72 = 0.15
1 yard is 36 inches. 2 yards is 72 inches. The question wants you to divide $10.80 into the inches that represent the yards. $10.80 / 72 = $0.15
Total emissions of carbon dioxide from the burning of fossil fuels have been increasing at about 5% per year (data from 2010 to 2011). If emissions continue to increase at this rate, about how much higher will total emissions be in 2035 than in 2010? Using the approximate formula, emissions will increase by a factor of between 2010 and 2035. Using the exact formula, emissions will increase by a factor of between 2010 and 2035. (Round to two decimal places as needed.)
Answer:
125%
Step-by-step explanation:
5% multipled by 25 years (from 2010 - 2035) = 125%
And i aint never seen to pretty best friendsssss
If emissions continue to increase at this rate, then about 125% higher total emissions will be in 2035 than in 2010.
What is the fundamental principlmultipliediplication?Multiplication is the mathematical operation that is used to determine the product of two or more numbers. If an event can occur in m different ways and if following it, a second event can occur in n different ways, then the two events in succession can occur in m × n different ways.
Given that Total emissions of carbon dioxide from the burning of fossil fuels have been increasing at about 5% per year.
Using the approximate formula, we can see that the emissions will increase by a factor of between 2010 and 2035.
Using the exact formula, it can be seen that the emissions will increase by a factor of between 2010 and 2035.
Therefore, 5% multipled by 25 years (from 2010 - 2035)
0.05 x 25 = 125%
If emissions continue to increase at this rate, then about 125% higher total emissions will be in 2035 than in 2010.
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Ratio of red to yellow marbles is 6 to 5 if there are 33 total marbles in the bag how many red
Answer:
18 red marbles and 15 yellow marbles.
Find three positive numbers whose sum is 100 and whose product is a maximum.
Answer:
The numbers are;
x = 100/3, y = 100/3, z = 100/3
Step-by-step explanation:
Given the data in the question;
so let the numbers be; x , y and z
so
x + y + z = 100
now
G(x,y,z) = x + y + z - 100
F(x,y,z) = xyz
Fx = yz, Gx = 1
Fy = xz, Gy = 1
Fz = xy, Gz = 1
Fx = λ × Gx
yz = λ
Similarly, xz = lambda
And xy = lambda
From above clearly, x = y = z
x + y + z = 100
so
3x = 100
x = 100/3
since, x = y = z therefore, each number is equal to 100/3
x = 100/3, y = 100/3, z = 100/3
We want to find 3 positive numbers such that their sum is 100 and the product is maximum.
The maximum product is P = 37,025.93
Let's say that our 3 numbers are:
A, B, and C.
We must have:
A + B + C = 100
The product of these 3 numbers is:
P = A*B*C
For the restriction, we can write:
A = 100 - B - C
Now we can replace that in the product equation to get:
P = (100 - B - C)*B*C
P = 100*B*C - C*B^2 - B*C^2
Now we want to maximize this, to do it, we need to find the zeros of the derivate of the function. This is a two-variable function, but the dependence on C is exactly the same as the dependence on B, so we can find the zero of deriving with respect to one of these only.
dP/dB = 100*C - 2*C*B - C^2 = 0
C*(100 - 2*B - C) = 0
One solution is C = 0, the other is:
C = 100 - 2*B
And from the first restroctopm:
A + B + C = 100
we can get:
C = 100 - A - B
Then:
100 - A - B = 100 - 2*B
Then we get A = B
And if we derive the equation for C instead of B, we will get similar results that will lead to:
A = B = C.
This is what maximizes the product, then we have:
A + B + C = 3*A = 100
A = 100/3 = 33.33
P = (33.33)^3 = 37,025.93
This is the maximum product.
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Jimmy earns money for babysitting his little
brother. He earns the same amount every
week. He is saving all the money he earns for a
summer trip. The table shows how Jimmy's
savings have been growing.
There are 36 carpenters in a crew. On a certain day, 29 were present. What percent showed up for work? (round to the nearest tenth)
(Please answer with explination)
Answer:
29/36*100 so ans will be 80.55555555555555555555555555555555555555
Step-by-step explanation:
Eduardo's football team has won
9/10
of their games this season.
Write
9/10
as a decimal.
Write
9/10
as a percent.
Answer:
9/10=0.9
9/10=90%
Step-by-step explanation:
Answer:
[tex]\frac{9}{10}[/tex] = 0.9
[tex]\frac{9}{10}[/tex] = 90%
Hope this help!
50+100n please awnser thisssssssssssssssssssssssssssssssssssssssssssssssss
Answer:
5 ( 1 + 20 n )
Step-by-step explanation:
Answer:
Your answer will be 150
Step-by-step explanation:
your answer going to be 150
which one of the mappings is a function?
Answer:
the answer is x.
Step-by-step explanation:
the x values are only being used once, therefore, it is a function
Sum of two numbers is -32 what number is two less than the other
First no. = z
Second no. = z - 2
z + (z - 2) = -32
z + z - 2 = -32
2z - 2 = -32
2z = -32 + 2
2z = -30
z = -30/2
z = -15
First no. = -15
Second no. = -17
ASAP HELP PLEASE ITS IS VERY NEEDED
Answer:
D. no solution because the other answers if you plug them in dont work
Which describes all decimals that are rational numbers?
Tbo dod
Answer:
Step-by-step explanation:
For starters, rational numbers are any numbers that has the capability to be written as a fraction.
For example, 0.5 is a decimal, and can also be written in form of a fraction, as 1/2
A recurring decimal can be written as a fraction. For example, we have 0.167 which can be written as 1/6
In the example, for the decimal 0.36425, we find the place value of the last digit. The last digit here is 5 placed in the hundred-thousandths place. On simplifying further into a fraction, we have 36425/100000.
Which best describes a polynomial?
Answer:
an algebraic expression containing one or more terms
Step-by-step explanation:
Mrs. jones bought 25 mangoes for $7.50. she sold 12 mangoes for 60 cents each and the remaining for 55 cents each. a. state whether she made a profit or loss b. calculate the profit loss c. calculate the percentage profit or loss
Answer:
when u search it one by one
E. You can see a person in 1/4 the windows, How many people are visable
Answer:
0
Step-by-step explanation:
You say that you can see a quarter of a person in a window. You cant have 1/4 of someone so the answer is 0 or 0.25