PLEASE HELP!
On a standardized exam, the scores are normally distributed with a mean of 155 and a standard deviation of 20. Find the z-score of a person who scored 145 on the exam.
Answer:
-0.5
Step-by-step explanation:
z-score = (x- mean)/SD
(145-155)/20 = -10/20 = -0.5
Answer:
Step-by-step explanation:
z=\frac{x-\mu}{\sigma}
z=
σ
x−μ
z-score formula
z=\frac{155-190}{20}
z=
20
155−190
Plug in values
z=\frac{-35}{20}
z=
20
−35
Subtract
z=-1.75
z=−1.75
Divide
\text{They scored 1.75 standard deviations below the mean.}
They scored 1.75 standard deviations below the mean.
What are the domain and points of discontinuity of y= x-4/x^2+8x-20? What are the x and y intercepts?
Step-by-step explanation: To find the x-intercept, substitute in 0 for y and solve for x.
x-intercept(s): (2.30581496,0)
y-intercept(s): None
Shota is a dangerous fellow who likes to go rock climbing in active volcanoes. One time, when he was 30 meters below the edge of a volcano, he heard some rumbling, so he decided to climb up out of there as quickly as he could. He climbed up at a constant rate. After 4.5 seconds, he was 7.5 meters below the edge of the volcano. How fast did Shota climb? In total, how long did it take Shota to reach the edge of the volcano?
Answer:
Shota's speed = 5 m/s
In total, it take 6 seconds to reach the edge of the volcano.
Step-by-step explanation:
Given;
Total height below the edge of the volcano = 30 m
(Note that he climbed at constant rate)
After 4.5 seconds, he was 7.5 meters below the edge of the volcano.
Time = 4.5 s
Distance covered = 30 - 7.5 = 22.5 m
His speed = distance covered/time
Substituting the values;
Speed = 22.5/4.5
Speed = 5 m/s
Time needed to reach the edge;
Time = distance/speed
Speed = 5m/s
Distance = 30 m
Substituting;
Time = 30/5 = 6 seconds
OVER HERE WALKER
What is the circumference of a circle with a diameter of 21 cm ?
Answer:
65.97
Step-by-step explanation:
Fiona draws a circle with a diameter of 14 meters. What is the area of Fiona’s circle?
Answer:
The area of the circle is [tex]153.94meters^2[/tex]
Step-by-step explanation:
The formula for the area of a circle is : [tex]\pi *radius^{2}[/tex]
To work this out you would first need to divide the diameter of 14 by 2, this gives you 7. This is in order for us to calculate the radius. The radius of a circle is the length from one side to the centre.
Now that we know the radius the next step is to multiply pi by the radius of 7 squared, this gives you 153.94. This is because in order for you to calculate the area you would substitute the values into the formula.
1) Divide 14 by 2.
[tex]14/2=7[/tex]
2) Multiply pi by 7 squared.
[tex]\pi *7^2=153.94 meters^2[/tex]
153.94 square meters is the area of the triangle.
What is Area?The area is the entire amount of space occupied by a flat (2-D) surface or an object's form. On a sheet of paper, draw a square using a pencil. It has two dimensions. The area of a form on paper is the area that it occupies.
The formula to calculate the area of a circle is A = πr², where A is the area and r is the radius of the circle.
Since the diameter is given as 14 meters, the radius can be calculated by dividing the diameter by 2:
r = d/2 = 14/2 = 7 meters
Now, we can substitute this value of radius into the formula for the area of a circle:
A = πr² = π(7)² = 49π square meters
Therefore, the area of Fiona's circle is 49π square meters (or approximately 153.94 square meters if π is approximated to 3.14).
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The product of two rational numbers is -28/81. If one of them is -2/3, then find the other.
PLEASE HELP....NEED TO SUBMIT IT NOW......
Answer:
14/27
Step-by-step explanation:
Let x be the unknown number
-2/3 * x = -28/81
Multiply each side by -3/2
-3/2*-2/3 * x = -28/81 * -3/2
x = 28/2 * 3/81
x =14*1/27
x = 14/27
Answer:
14/27
Step-by-step explanation:
Let x be the other number
x × -2/3 = -28/81
x = -28/81 × -3/2
x = 14/27
x² + 6x +8=0
In factoring algorithm
Answer:
(x+2)(x+4)
Step-by-step explanation:
Answer:
( x + 2 ) ( x + 4 )
Step-by-step explanation:
What is 2.95 expressed as a fraction?
33640
40118
11880
5920
Answer:
59/20
Step-by-step explanation:
good luck 8th grade k-12-ers!
A student is deriving the quadratic formula. Her first two steps are shown.
Step 1: –c = ax2 + bx
Step 2:
Which best explains or justifies Step 2?
Please consider the complete question.
A student is deriving the quadratic formula. Her first two steps are shown. Step 1: [tex]-c = ax^2 + bx[/tex]
Step 2: [tex]-c = a[x^2+\frac{b}{a}x][/tex]
Which best explains or justifies Step 2?
A. division property of equality
B. factoring the binomial
C. completing the square
D. subtraction property of equality
We can see that in step 2 student has factored the right side of equation.
The student factored our a from the right side of equation. To factor our a from right side, student has divide the bx term by a.
We can multiply and divide by same quantity in an equation.
[tex]-c = ax^2+a\cdot \frac{b}{a}x[/tex]
Now we can factor out a as:
[tex]-c = a(x^2+\frac{b}{a}x)[/tex]
Therefore, the 2nd step is known as factoring of binomial and option B is the correct choice.
Answer:
it b factoring a binomial on
Step-by-step explanation:
thats on edge
Find the parallelogram.
Answer:
area - 120 cm
Step-by-step explanation:
Answer:
A = 120 cm^2
P = 54 cm
Step-by-step explanation:
Area of parallelogram: = base * height
A = 15 cm * 8 cm = 120 cm^2
Perimeter of parallelogram = sum of lengths of sides
P = 15 cm + 15 cm + 12 cm + 12 cm = 54 cm
The table shows the results of an experiment in which a spinner was spun 50 times. Find the experimental probability of each outcome.
Answer:
Option "A" is the correct answer to the following question.
Step-by-step explanation:
Given:
Total number of experiment = 50
Find:
Probability to get less then 4:
Computation:
⇒ Total number can be get less then 4 = 4+2+3
⇒ Total number can be get less then 4 = 9
⇒ Probability of an outcome = Total number of outcomes / Total number of experiment
⇒ Probability to get less then 4 = Total number can be get less then 4 / Total number of experiment
⇒ Probability to get less then 4 = 9 / 50
WILL CHOOSE BRAINLIEST! PLEASE HELP! 15 POINTS!
Find the area of the shaded segment of the circle.
Answer:
The shaded segment = The arc area - The triangle
The arc area = pi x radius^2 x angle/360
= pi x 9^2 x (360-270)/360 = 63.61 (m2)
The triangle area = 9 x 9/2 = 41.5 (m2)
(because this is right triangle)
=> The shaded segment = 63.61 - 41.5 = 22.11 (m2)
Regina bought a book for $12 and a game for $14 she paid $40 how much change should Regina receive
Answer:Regina recieved $14 dollars of change
Step-by-step explanation:
12+14=26
40-26=14
The change received by Regina is $14.
What is a word problem?
A word problem is a verbal description of a problem situation. It consists of few sentences describing a 'real-life' scenario where a problem needs to be solved by way of a mathematical calculation.
For the given situation,
Regina bought a book for price = $12
Regina bought a game for price = $14
Total amount paid by Regina = $40
The Regina should receive the change,
⇒ [tex]Change = 40-(12+14)[/tex]
⇒ [tex]Change = 40-26[/tex]
⇒ [tex]Change = 14[/tex]
Hence we can conclude that the change received by Regina is $14.
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)
The scale model of a rectangular patio will be enlarged by a scale factor of 2.5 to create the actual patio. The actual patio will
be 15 feet by 20 feet. Which is the area of the scale model?
OOO
O 48 square feet
60 square feet
120 square feet
O 300 square feet
Answer:
48 square feet.
Step-by-step explanation:
Answer:48 sq ft
Step-by-step explanation:
i got it right on e d g e n u i t y
i hate people when they say have a good day! on here so…. have a bad day!
Teri has a bag of colored marbles. Five marbles are red, four are green, ten are blue, and one is white. Marbles are randomly selected out of the bag.
What is the probability of selecting a red marble and then a white marble without replacement?
Answer:
1/76
Step-by-step explanation:
Five marbles are red,
four are green,
ten are blue, and
one is white.
Sample space S= 5+4+10+1= 20
Probability of selecting a red Mable
Pr(red) = 5/20= 1/4
Probability of selecting a white Mable without replacement after the first selection
Pr(white) = 1/19= 1/19
the probability of selecting a red marble and then a white marble without replacement?
= 1/4*1/19= 1/76
Correct answers only please!
To the nearest cent, how much interest will she earn in 2 years?
Use the formula B = p(1 + r)t, where B is the balance (final amount), p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.
Answer:
$915.92
Step-by-step explanation:
i = p(1 + r)^t
i = $800(1 +.07)^2
i = $800(1.07)^2
$915.92
WILL MARK BRAINIEST!!!
What is the solution to the system of equations?
(−1, 3)
(1, −3)
(1, 3)
(−1, −3)
Answer:
(1,-3)
Step-by-step explanation:
What is the slope-intercept form of an equation of a line perpendicular to y=2x−3 and passing through the point (5,−1)?
Answer:
y=-2x+9
Step-by-step explanation:
1. Make m value opposite of og m value.
2. Then plug in variables x and y into the equation
3. Solve for b
-1 = -2(5) + b
9 = b
4. You have the answer
An author published a book which was being sold online. The first month the author
sold 15800 books, but the sales were declining steadily at 5% each month. If this
trend continues, how many total books would the author have sold over the first 11
months, to the nearest whole number?
Answer:
7110 books
Step-by-step explanation:
5%*15800=0.05*15800=790
790*11=8690
15800-8690=7110
Therefore, 7110 books
Answer: 86,900
Step-by-step explanation:
I changed the 5% into decimal form and made it 0.5. Next, I multiplied 0.5 by 11, which gave me 5.5.
15,800 x 5.5 = 86,900
So, the author would’ve sold 86,900 books in the first 11 months.
(Sorry if wrong. Yeah I think I’m wrong now because I’m not even in high school. Just ignore this lol)
The volume of a right rectangular prism can be found by finding the product 3(6)(12). Which expression could also be used to
determine the volume of this prism?
VX
36(6)
2(3 + 12 + 6)
4(3)(12)
12+6+3
Next
Submit
Save and Exit
Mark this and return
Activity
Answer:
a
Step-by-step explanation:
John is digging a rectangular hole. The area of the rectangle is 8 square feet. John digs 4 feet down into the ground. What is the volume of John's hole in cubic feet?
Answer:
32 cubic feet
Step-by-step explanation:
To know the volume of a figure we have to calculate the area of its "base" and then multiply it by its height.
In this case we have a rectangular hole that has an area of 8 square feet.
As we said before:
Volume = Area x height.
If we substitute the value of the area of the rectangle and the height (or depth in this case) we would get:
Volume = 8 x 4 = 32 cubic feet.
Thus, the volume of John's hole is 32 cubic feet.
Answer:
32 cubic feet
Step-by-step explanation:
The volume of a rectangular prism is given by;
Length*width*Height
or, Area*height
Height = 4 feet
Area= 8 square feet
Conversion to Cubic feet is given by;
(cubic feet) = (square feet) × (height in feet)
Therefore,
Cubic feet = 8 square feet*4 feet
= 32 cubic feet.
Find the equation of the axis of symmetry for the parabola y=x^2-5x+1/2
Answer:
The axis of symmetry is x = 5/2.
Step-by-step explanation: -b -(-5)
The formula for the axis of symmetry is x = -------- = --------- = 5/2
2a 2(1)
On a coordinate plane, a line is drawn from point C to point D. Point C is at (negative 1, 4) and point D is at (2, 0). Point C has the coordinates (–1, 4) and point D has the coordinates (2, 0). What is the distance between points C and D? D = StartRoot (x 2 minus x 1) squared + (v 2 minus v 1) squared EndRoot
Answer:
distance = 5 units
Step-by-step explanation:
In order to solve this problem we can start by plotting the two points you were provided with (see attached picture). This will help us visualize the problem better.
Now, we need to find the distance between those two points, so in order to do so we can use the distance formula:
[tex]distance = \sqrt{(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}}[/tex]
in this case the x's and y's are given by the given points, since they are written as ordere pairs. And ordered pairs are written in the form (x,y). So for Point C:
C=(-1,4)
[tex]x_{1}=-1[/tex]
[tex]y_{1}=4[/tex]
and for point D
D=(2.0)
[tex]x_{2}=2[/tex]
[tex]y_{2}=0[/tex]
so we can now use those values in our distance formula so we get:
[tex]d=\sqrt{(2-(-1))^{2}+(0-4)^{2}}[/tex]
[tex]d=\sqrt{(3)^{2}+(-4)^{2}}[/tex]
[tex]d=\sqrt{9+16}[/tex]
[tex]d=\sqrt{25}[/tex]
d=5 units.
Answer:
Point C has the coordinates (–1, 4) and point D has the coordinates (2, 0). What is the distance between points C and D?
d = StartRoot (x 2 minus x 1) squared + (v 2 minus v 1) squared EndRoot
5 units
Step-by-step explanation:
Just did it on Edg
It takes two men six hours to paint a fence. How long would it take three men to paint the same fence?
Answer:
Step-by-step explanation:
If 2 men take 6 hrs to paint the fence, then
3 men would obviously take less time to paint the same fence;
2 men= 6 hrs
3 men= ?
thus, the time taken by three men to paint the same fence=2/3 ×6 hrs
= 4 hrs
Gary needs to solve 120 problems by a certain day. He calculated, that to finish all the problems in time, he needs to solve 5 problems every day. But Gary's family is going on a trip, and for 4 days Gary will simply have no time to do math. How many problems will he need to be solving every day when he is not on a trip to still be done in time?
Answer:
To be done in time, he would need to solve 6 questions per day on the days that he is not on trip
Step-by-step explanation:
If he solves the problems 5 per day, the total number of days that would be required to finish solving the problem would be 120/5 = 24 days
Now, he has 4 free days which would be for a family trip. The number of questions that he would miss during those trip days will be 4 * 5 = 20 questions
Now since he wants to still finish on time, what is needed to be done is to share the 20 left overs amongst the 20 days which he has to work
This makes a total of 1 question per day
Adding this to the 5 questions per day he has before will be = 6 questions per day
Answer:
6 problems
Step-by-step explanation:
Please help ASAP! I will mark Brainliest! Please answer CORRECTLY! No guessing!
Answer:
The answer is D
I hope this is right
6. Which expression is equivalent to the
algebraic expression below?
3(2x - 1)
A. + 2
B. X-1
C. -6x .- 3
D. -6x - 1
Course 3/4 Benchmark Test - End of Year
Answer:
C. -6x . -3
Step-by-step explanation:
3 x 2x = 6x
3 x -1 = -3
How did mendeleev arrange the elements ?
A student solved this problem and said the answer was 5 1 4 14 miles. Danielle ran 3 1 8 18 miles on Tuesday, 4 1 2 12 miles on Wednesday, and 5 1 4 14 miles on Thursday. How far did Danielle run altogether? Is the student's answer reasonable? No, the answer is not reasonable. It should be about 13 miles. Yes, the answer is reasonable. No, the answer is not reasonable. It should be about 2 miles. No, the answer is not reasonable. It should be about 20 miles.
Question
A student solved this problem and said the answer was [tex]5\frac{1}{4}[/tex] miles. Danielle ran [tex]3\frac{1}{8}[/tex] miles on Tuesday, [tex]4\frac{1}{2}[/tex] miles on Wednesday, and [tex]5\frac{1}{4}[/tex] miles on Thursday. How far did Danielle run altogether? Is the student's answer reasonable?
- No, the answer is not reasonable. It should be about 13 miles.
- Yes, the answer is reasonable.
- No, the answer is not reasonable. It should be about 2 miles.
- No, the answer is not reasonable. It should be about 20 miles.
Answer:
- No, the answer is not reasonable. It should be about 13 miles.
Step-by-step explanation:
Given
Student solution = [tex]5\frac{1}{4}[/tex] miles.
Miles covered on Tuesday = [tex]3\frac{1}{8}[/tex] miles
Miles covered on Wednesday = [tex]4\frac{1}{2}[/tex] miles
Miles covered on Thursday = [tex]5\frac{1}{4}[/tex] miles
Required
- Total distance covered by the student
- Is the student answer reasonable?
To calculate the actual distance covered by Danielle, we simply add the distance covered on each day,
This goes thus
Distance = [tex]3\frac{1}{8}[/tex] + [tex]4\frac{1}{2}[/tex] + [tex]5\frac{1}{4}[/tex]
Convert to Improper Fractions
Distance = [tex]\frac{25}{8}[/tex] + [tex]\frac{9}{2}[/tex] + [tex]\frac{21}{4}[/tex]
Take LCM
Distance = [tex]\frac{25 + 36 + 42}{8}[/tex]
Distance = [tex]\frac{103}{8}[/tex]
Distance = 12.875
From the calculations above, we can conclude that the student's answe is not reasonable because his calculation ([tex]5\frac{1}{4}[/tex] miles) is much more smaller than the actual result 12.875 miles
From option A through D, Only option A is correct because 12.875 miles cam be approximated to 13 miles.
Hence,
A. - No, the answer is not reasonable. It should be about 13 miles.
is the right answer
11(4t + 1) whats the answer
Answer:
44t + 11
Step-by-step explanation:
[tex]11(4t + 1) \\ = 11 \times 4t + 11 \times 1 \\ = 44t + 11 \\ [/tex]
Answer:
the answer is attached to the picture
