Scores on a standardized test are normally distributed with a mean of 250 and a standard a deviation of 20. Approximately what percent of students scored between 260 and 280? Round to the nearest percent

Answers

Answer 1

Answer:

You can't answer this properly without more data.


Related Questions

i need the answer for


3-3 Mini Assessment | Constant of Proportionality in Graphs




Question
POSSIBLE POINTS: 1
The relationship between the number of ounces of tea purchased and the total cost of the tea is proportional as shown in the graph.



Which equation models this relationship?


y = 7/4x

y = 4/7x


y = 4/1x


y = 1/4x

Answers

Answer:  y= (7/4)x

Step-by-step explanation:

Build a table of representative values and then calculate the slope between any 2 of the points.   I'll pick (2,3.5) and  (8,14)    [See attachment. ]

The slope is the Rise/Run:

Rise = (14 - 3.5) = 10.5

Run = (8-2) = 6

Slope = Rise/Run:  (10.5/6) = 1.75

The equation should read y = 1.75x.  

None of the options works, as written, but note that 7/4 looks close to 1.75.  In fact, 7/4 = 1.75.

Use the equation y = 1.75x and enter several values of x (the ounces purchased) and y (the total cost of the purchase).  The attachment summarizes the results (Predicted), along with the actual values (Actual) taken from the graph.  Excellent correlation, considering the difficulty in making precise graph readings.

Therefore y = (7/4)x

Class 10R sat a test.
The mean mark for the class was 70%.

There are 30 students in class 10R, 20 of whom are boys.
The mean mark for the boys in the test was 62%.

Work out the mean mark for the girls.

Answers

Answer:

86%

Step-by-step explanation:

30 students in the class with a mean average of 70% can be expressed as:

total class percent / 30 = 70%

Rearranged, this gives that the class achieved a total of 30x70 or 2100%.

20 boys in the class with a mean average of 62% can be expressed as:

total boys percent / 20 = 62%

Rearranged, this gives that the boys achieved a total of 20x62 or 1240%.

This means that the girls achieved 2100 - 1240 so 860%.

Because there are 30 students and 20 boys, there are 10 girls.

Then work out the mean with a total of 860% and 10 girls.

860/10 = 86%.

Express in vertex form

Y=2x^2 - 2x - 5

Answers

Answer:

y = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex]

Step-by-step explanation:

y = 2x² - 2x - 5 ← factor out 2 from the first 2 terms

 = 2(x² - x) - 5

Using the method of completing the square

add/subtract (half the coefficient of the x- term)² to x² - x

y = 2(x² + 2(- [tex]\frac{1}{2}[/tex] ) x + [tex]\frac{1}{4}[/tex] - [tex]\frac{1}{4}[/tex] ) - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² + 2(- [tex]\frac{1}{4}[/tex] ) - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{1}{2}[/tex] - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex] ← in vertex form

 

Solving by Elimination

Answers

Answer:

unsolvable

Step-by-step explanation:

by elemination 14x+7y=-7 (1)

-14x-7y=7 (2)

x and y will be 0 then

If an atom has 5 protons, 7 neutrons and 5 electrons what is the mass number of the atom?
Please help quick!
No links!

Answers

Answer:

7+5=12

Step-by-step explanation:

To calculate the mass number of an atom, you have to add the protons and the neutrons. We have 7 neutrons and 5 protons, so your mass number would be 12. Let me know if you have any further questions. :)

Help me please save me from detention

Answers

Answer:

The answer is B.

Step-by-step explanation:

It would be B because,

2+2=4

4+2=6

6+4=10

10+6=16

Not A because,

1+1=2

2+1=3 not 4

There you go :) pls gime the crown... :)

what be the answer to this here mathematical equation and how do ye solve it? Asking for my pirate friend 7+x/3 = 2x-5

Answers

Answer:

YESSIR

Step-by-step explanation:

7⅕-2⅔x0,5 explain step by step

Answers

Step-by-step explanation:

7/5 - 2×2/3 × 0.5 = 1.4 - 2×0.5×2/3

= 1.4 - 1 ×2/3

=1/4 × 2/3

=1.5 - 0.6

? 2x² – 3x - y = -5
-x+y=5

Answers

Answer:

2x^2- 3x - Y= -5 -x + Y = 5

there is no solve because it already is solved.

Step-by-step explanation:

Draw an ordered stem and leaf diagram to show this information.



245, 250, 251, 253, 258, 264, 267, 269, 273, 276



Key:24|5 means 245.

Answers

Answer:  The filled out diagram is shown below

=========================================================

Explanation:

The key tells us how to set up the stem and leaf diagram. It says that [tex]24|5[/tex] represents the value 245.

This means that "24" is one of the stems. In fact, it's the smallest stem possible since there's nothing smaller than 240 on this given list of values.

The only leaf associated with this stem is 5. The stem 24 and the leaf 5 combine to form the number 245 as the key indicates.

--------------------------

In the next row is the stem 25. For this stem, we'll have the leaves of: 0, 1, 3, 8. The stem 25 and those leaves mentioned combine to form 250, 251, 253, 258 in that exact order. This time we'll use up four boxes for this row. The last box in this row is blank.

The remaining rows (stems 26 and 27) are handled in pretty much the same fashion. Let me know if you have questions how the boxes are filled in. It helps to start with sorted data from smallest to largest. Luckily, that's already been done for us.

The filled out chart is shown below. I replaced the stems 0,1,2,3 with 24,25,26,27.

When a system ofnliner equations has x-terms that are opposites how is x eliminated?​

Answers

Answer:

When the coefficients of one variable are opposites you add the equations to eliminate a variable and when the coefficients of one variable are equal you subtract the equations to eliminate a variable. We can eliminate the x-variable by addition of the two equations.

​ TV and WY areparallellines. S T U V W X Y Z Which angles are corresponding angles?

Answers

Answer:

A picture provided would be better, but here's a picture to help you find an answer to your question.

Step-by-step explanation:

The two angles marked in red are corresponding angles on a pair of parallel lines. Corresponding angles are ALWAYS congruent to each other.

Write an equation in slope-intercept form from the following points:
(-4,6) and (0,7)

Answers

Answer:

y = 1/4 * x + 7

Step-by-step explanation:

We start with the equation for slope-intercept y = mx + b -

Y is any y point on the line. X is any x point on the line. M is the slope of the line. B is the y-intercept of the line.

We first find the slope by using this equation (y2 - y1) / (x2 - x1) -

(7 - 6) / (0 - (-4))

1 / (0 + 4)

Slope = 1/4

Now we insert the slope into the equation -

y = 1/4 * x + b

As said before, Y is any y point on the line and X is any x point on the line, so we can choose a random point and insert it in to find the y-intercept -

(The equation already tells you the y-intercept (0, 7) but for checking, we will insert the point in too)

7 = 1/4 * 0 + b

7 = b

b = 7

The y-intercept of the line is (0, 7)

We insert the y-intercept in the equation -

y = 1/4 * x + 7

y = 1/4 * x + b is our answer to the problem.

If P(t) = 5e 0.89t
Then what is p(3)?
please!

Answers

Answer:

15.989

Step-by-step explanation:

i dont think you care

Which expressions are equivalent to a b/c

Answers

Answers:

[tex]\sqrt[c]{a^b}[/tex]

[tex](\sqrt[c]{a})^b[/tex]

Answer:

first 1 last 1 third 1 and forth 1

Step-by-step explanation:

Question 13 of 20
If fx) = 5x- 4 and g(x) = 4x+1, find (f- g)(x).

Answers

Answer:

Step-by-step explanation:

x-5

yo ill give brainliest if ur right help pls​

Answers

Answer:

B or C. Im thinking C.

Step-by-step explanation:

Answer:

C, look at the problem and it says plus" directly look at the option and compare.

Step-by-step explanation:

A Carpenter wants to build a elliptical table top from a 4 foot to by 6 foot sheet of plywood. she traces out the ellipse using a string attached to thumbtacks located at the foci of the ellipse.

Answers

The thumbstacks have an in-between distance of [tex]2\sqrt{5}[/tex] feet.

The distance between any focus and the center of the ellipse ([tex]c[/tex]), in feet, is described by the following expression:

[tex]c = \sqrt{a^{2}-b^{2}}[/tex] (1)

Where:

[tex]a[/tex] - Major semiaxis length, in feet.[tex]b[/tex] - Minor semiaxis length, in feet.

If we know that [tex]a = 3\ft[/tex] and [tex]b = 2\,ft[/tex], then the distance between focus and center is:

[tex]c = \sqrt{3^{2}-2^{2}}[/tex]

[tex]c = \sqrt{5}[/tex]

The distance between the thumbstacks is described by this expression:

[tex]d = 2\cdot c[/tex]

[tex]d = 2\sqrt{5}\,ft[/tex]

The thumbstacks have an in-between distance of [tex]2\sqrt{5}[/tex] feet.

We kindly invite to check this question on ellipses: https://brainly.com/question/14281133

Given f(x)=-x-4f(x)=−x−4, find f(4)f(4).

Answers

Answer:

1/4 or .25

Explanation

As for this specific question algebra is something I do in my head and skip many steps for however if you want to proof my answer it would be this.

-0.25-16*.25=-0.25-4

-0.25-4=-0.25-4

-4.25=-4.25

For the function  f(x) = -x-4 the value of f(4) is -8.

The given function is f(x) = -x-4.

We need to find the value of f(4).

To find this we have to replace the x value with 4.

Substitute x=4 in the function:

f(4)=-4-4

f(4)=-8

Hence, the value of f(4) is -8.

To learn more on Functions click:

https://brainly.com/question/30721594

#SPJ3

1.what is the y-intercept f (x) = 3x+8/x-4?
a.-2
b.0
c.2
d.4
2.the horizontal asymptote of f (x) = 2x+5/x^2-3x+2?
a. y = -1
b. y = 0
c. y = 1
d. y = 2
3. what is the x - intercept of f (x) = 2x+6/x-1?
a.-5
b.-3
c.-1
d.0
4.what is the vertical asymptote of f (x) = x^2+5x+6/x-5?
a.x = -6
b.x = 0
c.x = 5
d.x = 6
5. what is the zero of f (x) = x^2-25/x+5?
a.-5
b.0
c.5
d.25
6.the oblique asymptote of f (x) = x^2=3x-5/x+2?
a.y = x + 1
b.y = x + 2
c.y = x + 3
d.y = x + 5

Answers

The Eubanks Answer:

Step-by-step explanation:hehus

PLEASE HELP ME ASAP!!!!

4 5/9 is the same as the sum of 2 1/3 and 5/6 times a number.

What is the number?

Enter your answer as a mixed number in simplest form in the box.

PLEASE ANSWER QUICK!!

Answers

Answer:

2 2/3

Step-by-step explanation:

randall wants to fill up 40 percent of the scare containers. what is this number as a fraction

Answers

the answer is 4/10 i believe

Answer:

2/5

Step-by-step explanation:

Normally, percentage is expressed in 0 - 100 so for Randall to fill up 40% of his container, that means he'd fill out 40 out of a hundred. That's 40/100 which simplified will give you 2/5

Elise says, "If you subtract 17 from my number and multiply the difference by -3, the result is -61."
What is Elise's number?

Answers

Answer:

Elise's number is 112/3.

Step-by-step explanation:

You can form the equation: [tex]\left(x-17\right)\cdot -3=-61[/tex]

Solution: [tex]\frac{\left(x-17\right)\left(-3\right)}{-3}=\frac{-61}{-3}[/tex]

[tex]x-17=\frac{61}{3}[/tex]

[tex]x-17+17=\frac{61}{3}+17[/tex]

x=112/3

line j passes through the point (-4,10) and (2,-8). Line k passes through the point (1,2) and is parallel to line j. Find an equation for line k.

Answers

Answer:

344444444433333338694

Step-by-step explanation:

Answer: y = -3x+5

Step-by-step explanation:

I need help with this Pre-Cal question

Answers

Answer:

Step-by-step explanation:

I need help finding the rule.

Answers

Answer:

y=3x+1

Step-by-step explanation:

The question is asking for an equation in slope-intercept form. This is y=mx+b, where m is slope and b is y-intercept. The slope is the change is y over the change in x. The y value changes 3 and the x value changes 1. So, the slope is 3/1 or just 3. The y-intercept is the value where the line intersects with the y-axis. Additionally, the y-intercept will have an x-value of 0. On the table, you can see that y=1 when x=0. Thus, the y-intercept is 1. Put the two values into the equation and you get y=3x+1.

Meera is choosing 2 books from the library. She is choosing from a selection of Science fiction, Biography and thriller. She can choose more than one of the same type. Write down all the combinations of two books that she could take​

Answers

Step-by-step explanation:

She could take two science fiction, two biography, two thriller, one thriller and one science fiction, one thriller and one biography, one science fiction, and one biography

Answer: 3

Step-by-step explanation:

Science Fiction: SF

Biography: BI

Thriller: TH

SF:BI, TH

BI:TH

pls help me for my geometry class

Answers

Answer:

I CANT SEE SRY

Step-by-step explanation:

express the followinf percentage as a fraction
a) 6 3/5%

Answers

Answer:

6.6/100 or 3.3/5

Step-by-step explanation:

6.6% or 6 3/5% now since those are all out of 100 (since percentages) you just put #/100 and get your fraction

How do you solve 100^(5x+2)=1000^(4x-1)?

Answers

This whole equation is also equal to 10^10(5x+2)=10^100(4x-1). From there you can divide both sides by 10 and distribute on both sides. From there, it’s just basic algebra
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