A 90% confidence interval is found to be (120, 140). What is the margin of
error?

Possible intervals are ( 120 ±12, 140 ±14) , ( 120, 140 ±14)  , ( 120 ±12, 140)

Step-by-step explanation:

Here, we have A 90% confidence interval is found to be (120, 140).

There are various Cases possible as:

Case 1:

There is 10% error in both minimum and extreme values i.e. 120 & 140 ,

Error in 120 is 10% i.e. = 12, Since value can be more or less in error ∴ Error in 120 is ±12.

Similarly, Error in 140 is 10% i.e. = 14, Since value can be more or less in error ∴ Error in 140 is ±14.

Possible intervals are ( 120 ±12, 140 ±14).

Case 2:

There is error in 120 only, ∴ Error in 120 is ±12.

Possible intervals are ( 120 ±12, 140).

Case 3:

There is error in 140 only, ∴ Error in 140 is ±14.

Possible intervals are ( 120, 140 ±14).

step-by-step explanation:

equation

you are asked to write the equation

  expression = 0

using the given expression. when you do that, you have

  2x^2-2x-12 = 0

factoring

you can see that each of the coefficients is even, so a factor of 2 can be removed immediately.

  2(x^2 -x -6) = 0

if you multiply the binomials (x+a)(x+b), you get

  (x +a)(x +b) = x^2 +(a+b)x +ab

this tells you the coefficient of x is the sum of two factors of the constant term. here, that means -1 is the sum of two factors of -6. we want to know those factors so we can factor the trinomial.

  -6 = -1×6 = -2×3 = -3×2 = -6×1

the factor pair that sums to -1 is {-3, 2}, so our factorization is

  2(x -3)(x +2) = 0

solutions

the solutions to this equation are the values of x that make the product zero. a product is zero only when only of the factors of the product is zero. here, that means

  x - 3 = 0

  x = 3 . . . add 3 to both sides of the equation

or

  x +2 = 0

  x = -2 . . . add -2 to both sides of the equation

the solutions to the equation are x=3 or x=-2. both of these values of x satisfy the equation—they make it be true.

answer: c

step-by-step explanation: because you don't have to draw a point of intersection. couldyou give me brainliest?

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