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3 years ago

Which is the equation of a line with a slope of -2 and passes through the point of (3,-4)

Mathematics

1 answer:

lisabon 2012 [21]3 years ago

5 0

Answer:

2x + y = 2

Step-by-step explanation:

y = -2x + b

-4 = -2(3) + b

-4 = -6 + b

2 = b

y = -2x + 2

2x + y = 2

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A(n) _____ is the set of possible values for a given attribute

Sladkaya [172]

I think this is the Domain. Since a domain is a group of numbers that can be entered in a function to create a valid output. They are set of all possible values of x which will satisfy a ffunction and output real y-values

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3 years ago

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Sophie [7]

Answer:

Step-by-step explanation:

I graphed it but you could also use the y intercept to determine which function matches the graph

log(x+1)<u>+3</u>

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Grace is comparing cell phone plans. A prepaid phone plan costs $0.20 per minute and has no monthly fee. A contracted phone plan

Sophie [7]

Answer:

Step-by-step explanation:

The contracted phone plan will have the same steepness and a higher y-intercept.

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3 years ago

A collection of dimes is arranged in a triangular array with 17 coins in the base row, 16 in the next, 15 in the next, and so fo

Crazy boy [7]

Answer:

153 coins will be there.

Step-by-step explanation:

The number of coin in the bottom row / or last row = 17

The number of coins in the second last row = 16

The number of coins in the second row = 2

The number of coins in the first row = 1

So the total number of coins = (Number of coin in the first row) + (Number of coins in the second row) + (Number of coins in the third row) + ....... + (Number of coins in the last row / seventeenth row)

Total number of coins = 1+2+3+....+16+17

Total number of coins = $\frac{17\times(17+1)}{2}=\frac{17\times18}{2}=17\times9=153$

(NOTE: Sum of first n natural number = $\frac{\boldmath n\times(n+1)}{2}$ )

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3 years ago

A sample of 100 cars driving on a freeway during a morning commute was drawn, and the number of occupants in each car was record

makkiz [27]

Answer:

$E(X)=1*0.74 +2*0.1 +3*0.11+ 4*0.03 +5*0.02=1.49$

$Var(X)=E(X^2)-[E(X)]^2 =3.11-(1.49)^2 =0.8899$

$Sd(X)=\sqrt{Var(X)}=\sqrt{0.8899}=0.943$

Step-by-step explanation:

For this case we have the following data given:

X 1 2 3 4 5

F 74 10 11 3 2

The total number of values are 100, so then we can find the empirical probability dividing the frequency by 100 and we got the followin distribution:

X 1 2 3 4 5

P(X) 0.74 0.10 0.11 0.03 0.02

Previous concepts

In statistics and probability analysis, the expected value "is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values".

The variance of a random variable Var(X) is the expected value of the squared deviation from the mean of X, E(X).

And the standard deviation of a random variable X is just the square root of the variance.

Solution to the problem

In order to calculate the expected value we can use the following formula:

$E(X)=\sum_{i=1}^n X_i P(X_i)$

And if we use the values obtained we got:

$E(X)=1*0.74 +2*0.1 +3*0.11+ 4*0.03 +5*0.02=1.49$

In order to find the standard deviation we need to find first the second moment, given by :

$E(X^2)=\sum_{i=1}^n X^2_i P(X_i)$

And using the formula we got:

$E(X^2)=1^2 *0.74 +2^2 *0.1 +3^2 *0.11 +4^2 0.03 +5^2 *0.02=3.11$

Then we can find the variance with the following formula:

$Var(X)=E(X^2)-[E(X)]^2 =3.11-(1.49)^2 =0.8899$

And then the standard deviation would be given by:

$Sd(X)=\sqrt{Var(X)}=\sqrt{0.8899}=0.943$

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3 years ago