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3 years ago

What is the standard deviation of a normal distribution, whose mean is 35, in which an x-value of 23 has a z-score of -1.63?

Mathematics

1 answer:

Dvinal [7]3 years ago

6 0

Answer:

7.36

Step-by-step explanation:

z-score is:

z = (x − μ) / σ

Given that z = -1.63, x = 23, and μ = 35:

-1.63 = (23 − 35) / σ

σ ≈ 7.36

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Y=-0.72x + 7.7 Find y when x = 3.5.

OLEGan [10]

Answer:

y = 5.18

Step-by-step explanation:

replace x in the equation with 3.5

y = -0.72x + 7.7

y = -0.72(3.5) + 7.7

y = -2.52 + 7.7

y = 5.18

7 0

2 years ago

Read 2 more answers

Simplify 2(a-3)/(a-4)(a-5)+(a-1)/(3-a)(a-4)+(a-2)/(5-a)(a-3)

Umnica [9.8K]

Answer:

$\dfrac{5}{x^3-12x^2+47x-60}$

Step-by-step explanation:

Though it is not what you have written, we think you want to simplify ...

$\dfrac{2(a-3)}{(a-4)(a-5)}+\dfrac{(a-1)}{(3-a)(a-4)}+\dfrac{(a-2)}{(5-a)(a-3)}\\\\=\dfrac{2(a-3)^2}{(a-3)(a-4)(a-5)}+\dfrac{-(a-1)(a-5)}{(a-3)(a-4)(a-5)}+\dfrac{-(a-2)(a-4)}{(a-3)(a-4)(a-5)}\\\\=\dfrac{2(a^2-6a+9)-(a^2-6a+5)-(a^2-6a+8)}{x^3-12x^2+47x-60}\\\\=\boxed{\dfrac{5}{x^3-12x^2+47x-60}}$

_____

When writing a fraction in plain text, parentheses are needed around the entire denominator. The order of operations tells you that a/bc = (a/b)c, not a/(bc).

6 0

2 years ago

Franky's age is 5 years less that 1/2 his mothers age. If Franky is 13 years old,write an equation to determine his mothers age

Alik [6]

Answer:

1/2x-5=13

Step-by-step explanation:

Let x= Frankie’s mother’s age

Half his mother’s age= 1/2x

5 less than that=1/2x-5

We know that Frankie is 13 so that equation is equal to Frankie’s age, which is 13.

Hope this helps.

4 0

3 years ago

Can each pencil have a mass of 10.5 grams in a pack of 5 pencils weighing 60 to 95 grams?

kvasek [131]

I don't know if I'm right, but if each pencil is 10.5 grams then you multiply it by 5 ( number of pencils) and you get 52.5, which would not meet the standards of a pack weighing 60 to 95 grams.

8 0

3 years ago

Plz help me answer this

timofeeve [1]

Answer:

(-2, -8)

x = -2

y = -8

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS
Equality Properties

Algebra I

Solving systems of equations using substitution/elimination

Step-by-step explanation:

Step 1: Define systems

13x - 6y = 22

x = y + 6

Step 2: Solve for y

Substitution

Substitute in x: 13(y + 6) - 6y = 22
Distribute 13: 13y + 78 - 6y = 22
Combine like terms: 7y + 78 = 22
Isolate y term: 7y = -56
Isolate y: y = -8

Step 3: Solve for x

Define original equation: x = y + 6
Substitute in y: x = -8 + 6
Add: x = -2

4 0

3 years ago