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3 years ago

Statistics how do we determine a percentage

1 answer:

7 0

Percent simply means "per hundred" and the symbol used to express percentage is %. One percent (or 1%) is one hundredth of the total or whole and is thereforecalculated by dividing the total or whole number by 100. To calculate the percentagedifference between two numbers, the same basic calculations are used

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If f (x) = mx+c, f(4) = 11 and f (5)=13 find value of m and c

inysia [295]

m=2 and c=3

see the attachment for the detailed solution

8 0

2 years ago

MAX POINTS!!! Write and solve a system of equations. Be sure to label the variables. The difference of two numbers is two. Two t

Cerrena [4.2K]

Answer:

5 and 3

Step-by-step explanation:

Let the numbers be x and y.

The equations are:

x - y = 2
2x + y = 13

Add up the equations to eliminate y and solve for x:

x - y + 2x + y = 2 + 13
3x = 15
x = 15/3
x = 5

Now find the value of y:

y = x - 2
y = 5 - 2
y = 3

3 0

2 years ago

Read 2 more answers

line segment with one endpoint at (2,5) is divided in the ratio 4:5 by the point (10,1). which coordinates could represent the o

rodikova [14]

Answer:

(20,-4)

Step-by-step explanation:

We are given;

One end point as (2,5)

Point of division as (10,1)

The ratio of division as 4:5

We are required to calculate the other endpoint.

Assuming the other endpoint is (x,y)

Using the ratio theorem

If the unknown endpoint is the last point on the line segment;

Then;

$\left[\begin{array}{ccc}10\\1\end{array}\right]$ = $\frac{4}{5} \left[\begin{array}{ccc}x\\y\end{array}\right]$ + $\frac{5}{9}\left[\begin{array}{ccc}2\\5\end{array}\right]$

Therefore; solving the equation;

$10=\frac{4}{9}x+\frac{10}{9}$

solving for x

x = 20

Also

$1=\frac{4}{9}y+\frac{25}{9}$

solving for y

y= -4

Therefore,

the coordinates of the end point are (20,-4)

5 0

2 years ago

The value of y varies directly as x with a constant variation of 2 what is the value of y when x is 6?

sp2606 [1]

Answer:

The value of y is 12

Step-by-step explanation:

y∝x

y = kx

y = 2x

when x = 6, y = 2(6)

= 12

(Correct me if i am wrong)

8 0

2 years ago

the marks in an examination for a Physics paper have normal distribution with mean μ and variance σ2 . 10% of the students obtai

ipn [44]

Answer:

The mean of the distribution is about 53.9 and standard deviation is about 16.5 marks.

Step-by-step explanation:

Use the trick of transforming the given random variable one that is standard normal distributed, aka a z-score, then look up the two percentile values in z-score tables to get two equations with two unknowns.

So, let x be the variable describing the marks of a student, and

$z=(x-\mu)/\sigma$

the standardized equivalent of that (mu - mean, sigma - standard deviation).

We are looking for values of mu and sigma. At this point we'd be out of luck, but, wait, we're given two bits of info: the 10% point (aka, 90th percentile) and the 20% point (can be interpreted as 100-20th percentile). For each point we can use z-score tables to look up the corresponding values of z (just search for z tables). I found:

z-score for the 10% point: z_10=1.28

z-score for the 20% point: z_20=-0.84

That gives us two equations:

$z_{10}=1.28=(75-\mu)/\sigma\\z_{20}=-0.84=(40-\mu)\sigma$

and can be solved for mu and sigma (do the work on your end, I am showing my result):

$\mu=53.87\,\,,\,\, \sigma=16.51$

The mean of the distribution is about 53.9 and standard deviation is about 16.5 marks.

3 0

2 years ago