Ask question

Ask question

All categories

igor_vitrenko [27]

3 years ago

13

HELP ASAP FOR BRAINLIEST: The time required to finish a test is normally distributed with a mean of 60 minutes and a standard de

viation of 10 minutes. What is the z-score for a student who finishes the test in 45 minutes? Show work!

1 answer:

Natali [406]3 years ago

5 0

Answer: the z score is - 1.5

Step-by-step explanation:

Since the time required to finish a test is normally distributed, we would apply the formula for normal distribution which is expressed as

z = (x - µ)/σ

Where

x = time required to finish the test

µ = mean time

σ = standard deviation

From the information given,

µ = 60 minutes

σ = 10 minutes

We want to find the z-score for a student who finishes the test in 45 minutes

For x = 45,

z = (45 - 60)/10 = - 15/10 = - 1.5

You might be interested in

(31x15)108divided by6

harina [27]

Answer:

8370

Step-by-step explanation:

(31x15)108 = (465)108

= 50220/6

= 8370

5 0

3 years ago

Read 2 more answers

Find all solutions <br> 36x²+12x=0

FromTheMoon [43]

Answer:

x = -1/3 or 0

Step-by-step explanation:

Given equation:

$36x^{2} + 12x = 0$

We can factor 12x on the L.H.S since 12x is divisible by 36x² and 12x.

$\implies 36x^{2} + 12x = 0$

$\implies 12x(3x + 1) = 0$

This can lead to two solutions. I have listed them below!

<h2>Solution 1:</h2>

Divide 12x on both sides to open the parentheses.

$\implies 12x(3x + 1) = 0$

$\implies \dfrac{12x(3x + 1)}{12} = \dfrac{0}{12}$

<em>Note: zero divided by any non-zero number is 0.</em>

$\implies \dfrac{12x(3x + 1)}{12} = \dfrac{0}{12}$

$\implies 3x + 1 = 0$

Isolate 3x on one side of the equation.

$\implies 3x + 1 = 0$

$\implies 3x = 0 - 1$

$\implies 3x = -1$

Divide 3 both sides to determine the value of x.

$\implies 3x = -1$

$\implies \dfrac{3x}{3} = \dfrac{-1}{3}$

$\implies \boxed{x = \dfrac{-1}{3}}$

<h2>Solution 2:</h2>

Divide (3x + 1) on both sides to isolate 12x.

$\implies 12x(3x + 1) = 0$

$\implies \dfrac{12x(3x + 1)}{(3x + 1)} = \dfrac{0}{(3x + 1)}$

<em>Note: zero divided by any non-zero number is 0.</em>

$\implies \dfrac{12x(3x + 1)}{(3x + 1)} = \dfrac{0}{(3x + 1)}$

$\implies 12x = 0$

Divide 12 both sides to determine the value of x.

$\implies 12x = 0$

$\implies \dfrac{12x}{12} = \dfrac{0}{12}$

$\implies \boxed{x = 0}$

Therefore, the solutions for x are -1/3 or 0.

Learn more about this topic: brainly.com/question/295675

5 0

2 years ago

Read 2 more answers

Are the ratios 3:6 and 6:3 equivalent?

KATRIN_1 [288]

Yes they are cause 3 of 6 and 6 of 3

4 0

3 years ago

Read 2 more answers

Verify each trigonometric equation by substituting identities to match the right hand side of the equation to the left hand side

lorasvet [3.4K]

Answer:

Step-by-step explanation:

1.

cot x sec⁴ x = cot x+2 tan x +tan³x

L.H.S = cot x sec⁴x

=cot x (sec²x)²

=cot x (1+tan²x)² [ ∵ sec²x=1+tan²x]

= cot x(1+ 2 tan²x +tan⁴x)

=cot x+ 2 cot x tan²x+cot x tan⁴x

=cot x +2 tan x + tan³x [ ∵cot x tan x $=\frac{ \textrm{tan x }}{\textrm{tan x}}$ =1]

=R.H.S

2.

(sin x)(tan x cos x - cot x cos x)=1-2 cos²x

L.H.S =(sin x)(tan x cos x - cot x cos x)

= sin x tan x cos x - sin x cot x cos x

$=\textrm{sin x cos x }\times\frac{\textrm{sin x}}{\textrm{cos x} } - \textrm{sinx}\times\frac{\textrm{cos x}}{\textrm{sin x}}\times \textrm{cos x}$

= sin²x -cos²x

=1-cos²x-cos²x

=1-2 cos²x

=R.H.S

3.

1+ sec²x sin²x =sec²x

L.H.S =1+ sec²x sin²x

= $1+\frac{{sin^2x}}{cos^2x}$ [ $\textrm{sec x}=\frac{1}{\textrm{cos x}}$ ]

=1+tan²x $[\frac{\textrm{sin x}}{\textrm{cos x}} = \textrm{tan x}]$

=sec²x

=R.H.S

4.

$\frac{\textrm{sinx}}{\textrm{1-cos x}} +\frac{\textrm{sinx}}{\textrm{1+cos x}} = \textrm{2 csc x}$

L.H.S= $\frac{\textrm{sinx}}{\textrm{1-cos x}} +\frac{\textrm{sinx}}{\textrm{1+cos x}}$

$=\frac{\textrm{sinx(1+cos x)+{\textrm{sinx(1-cos x)}}}}{\textrm{(1-cos x)\textrm{(1+cos x})}}$

$=\frac{\textrm{sinx+sin xcos x+{\textrm{sinx-sin xcos x}}}}{{(1-cos ^2x)}}$

$=\frac{\textrm{2sin x}}{sin^2 x}$

= 2 csc x

= R.H.S

5.

-tan²x + sec²x=1

L.H.S=-tan²x + sec²x

= sec²x-tan²x

= $\frac{1}{cos^2x} -\frac{sin^2x}{cos^2x}$

$=\frac{1- sin^2x}{cos^2x}$

$=\frac{cos^2x}{cos^2x}$

=1

8 0

4 years ago

Find an equation for a line with slope of 3/4 passing through (2, -3)

murzikaleks [220]

Answer:

y=3/4x-9/2

Step-by-step explanation:

7 0

3 years ago