A scientist is studying the effects of cell phone use on headache rate. She identifies 30 people who use cell phones and 30 who do not. Each of the 60 people is given a questionnaire designed to determine headache frequency. None of the 60 people who participated in the study knew they were part of a study. Which statement is true?

Answer:

B

Step-by-step explanation:

correct on edge

The answer is, sin (2x)=4√21/25

Trigonometry is a branch of mathematics that studies relationships between side lengths and angles of triangles.

Here, given that,

sin(x)=2/5

and tan(x)>0

Then, cos(x)=√21/25

tan(x)=2/√21

Now, sin (2x)=2tan(x)/1+tan²(x)

                    =0.873/1.19

                    =0.733

                    =4√21/25

To learn more trigonometry click:

https://brainly.com/question/26719838

#SPJ2

9514 1404 393

Answer:

  C.  distance formula

Step-by-step explanation:

If you're starting from vertex coordinates, the distance formula is appropriate for finding the length of one side of a parallelogram. It will tell you the distance between two points:

  d = √((x2-x1)² +(y2-y1)²)

Answer:

y = -3/4x - 6

Step-by-step explanation:

Answer:

500+4=504

Step-by-step explanation:

Hope it helps

Answer:

maybe 35 is the answer for the it

Answer:

by referencing the source

after sentence 2

Step-by-step explanation:

edge2020

Answer:

95% confidence interval for the mean μ is (6,14)

The Population mean μ lies between ( 6, 14 )

Step-by-step explanation:

Explanation:-

Given random sample 'n' = 1200

95% confidence interval for the mean μ is determined by

        [tex](x^{-} -Z_{\alpha } \frac{S.D}{\sqrt{n} } , x^{-} +Z_{\alpha } \frac{S.D}{\sqrt{n} } )[/tex]

Level of significance = 95% 0r 0.05

Z₀.₀₅ = 1.96

   [tex](x^{-} -Z_{\alpha } \frac{S.D}{\sqrt{n} } , x^{-} +Z_{\alpha } \frac{S.D}{\sqrt{n} } )[/tex] = 10 ± 4

Mean of the small sample = 10

95% of confidence intervals are

                         ( 10 ±4 )

                  ( 10 -4 , 10+4)

                  ( 6 , 14 )

95% confidence interval for the mean μ lies between ( 6, 14 )

Answer:

AB is parallel to CD - the reasoning looks right aswell although I don't know exactly what I'm answering here.. are you asking to check it?

Answer:

30 remainder 1 or 30.5

Step-by-step explanation:

please make me brainliest

Answer:

3 Lemonade

Step-by-step explanation:

We add $1.00 with $0.10, then we get $1.10

We then divide $1.10 to the amount Sara paid

$3.60/1.10, we will get the answer 3

Please find illustration attached

Answer and explanation:

I have illustrated the bisection of the lines using a diagram so it's easier to solve length of AB

Comparing line DE and CB, we know that DE is half of line DC and DC is half of CB, because CB= AC

Therefore DE is a quarter of line CB because length of DE × 4 will be equal to CB

To find length of AB, we go from known to unknown

We know from what we are given that line AB has a midpoint C, CB in line AB = 3x²+3x

CB=AC because CB is half of line AB

Therefore line AB

=3x²+3x+3x²+3x

= 6x²+6x

Please find diagram attached

Answer and explanation:

Perpendicular lines are lines that meet at 90 degrees/ right angle.

The question seems to be incomplete but I will explain what perpendicular lines are in the context of lines lll and mmm, with some assumptions about the lines.

Assume that line III is 30mm long and line mmm is 25mm long, we say that line III is perpendicular to line mmm if line III meets line mmm at 90 degrees as we see in the diagram attached.

Answer:

n=7

m= 7[tex]\sqrt{3}[/tex]

Step-by-step explanation:

lmk if you need work

Answer:

Step-by-step explanation: 16,888 this are the answer

Answer:

y=x+2

y=-x+8

Step-by-step explanation:

Answer: 7m + 5

Step-by-step explanation:

Distribute the Negative Sign:

=12m+1+−1(5m−4)

=12m+1+−1(5m)+(−1)(−4)

=12m+1+−5m+4

Combine Like Terms:

=12m+1+−5m+4

=(12m+−5m)+(1+4)

=7m+5

-2/15=13/15

Step-by-step explanation:

2/3-4/5=13/15

2/15=13/15

2+1= 3

So is three ;-;?

Answer:

THERE U GO

Step-by-step explanation:

HOPE THIS HELPS

Answer:

I mean it would just be q(x) = 0

Step-by-step explanation:

Answer: q=0

Step-by-step explanation: Let's solve for q.

qx=2−2

Step 1: Divide both sides by x.

qx

x

=

0

x

q=0

Answer:

q=0

Answer: I need a picture to find out ;-;

Step-by-step explanation:

Answer:

if youre asking for the equation its AB=CD

Step-by-step explanation:

If youre not, you'll need to attach a file or smth :'D

Answer:

35 degrees

42 degrees

x = 8 degrees

x = 7 degrees

Step-by-step explanation:

1)

m <1 = 70/2 = 35 degrees

2)

m <1 = 84/2 = 42 degrees

3)

6 + 4 x = (9 x + 4) / 2

12 + 8 x = 9 x + 4

12 - 4 = x

x = 8 degrees

4)

3 x - 1 = x + 13

2 x = 14

x = 7 degrees

Answer:   10°

__________________________________________________________

We are given:

Sin(6θ)  = Cos(3θ)

Solving for θ:

Simplifying Cos(3θ):

We know that:  

Cos(θ) = Sin(90-θ)

So, we can say that:

Cos(3θ) = Sin(90 - 3θ)

Finding the value of θ:

Sin(6θ) = Cos(3θ)

Sin(6θ) = Sin(90 - 3θ)                             [Since Cos(3θ) = Sin(90 - 3θ)]

6θ = 90 - 3θ                                            [If Sin(θ) = Sin(A) ; θ = A]

9θ = 90                                                   [adding 3θ on both sides]

θ = 10°                                                     [dividing both sides by 9]

Answer: 1200

Step-by-step explanation:

Answer:

192

Step-by-step explanation:

First, you would divide 480 by 10 to get 48 because you divide by the number of hours.

Then, multiply 48 by 4 to get your answer.

The answer: 192

Note: You missed to add some of the details of the question.

Hence, I am solving your concept based on an assumed graph which I have attached. It would anyways clear your concept.

Answer:

Please check the explanation.

Step-by-step explanation:

Given the right angled-triangle ABC as shown in the attached diagram

From the triangle:

Ф= ∠C = 30°

AB = 6 units

BC = y

tan Ф = opp ÷ adjacent

The opposite of ∠C = 30°  is the length '6'.

The adjacent of ∠C = 30°  is the length 'y'.

As Ф= ∠C = 30°

so

tan Ф = opp ÷ adjacent

tan 30 = 5  ÷ y

1 ÷ √3 = 5  ÷ y

y = 8.7 units

Therefore, the length of the unknown side length 'y' is 8.7 units.

Answer:

17

Step-by-step explanation:

Answer:

x = 23

Step-by-step explanation:

3x + 4x + 19 = 180

7x + 19 = 180

7x = 161

x = 23

Answer: x = pi/6 and x = pi/3.

Step-by-step explanation:

We have the function:

y = x + 2*cos(x)

It will have a horizontal tangent at the point where it's derivate is equal to zero.

Then first let's differentiate y.

y' = dy/dx = 1 - 2*sin(x).

Then we must find the value of x between 0 and 2*pi (or 0° and 360°)

y'(x) = 1 - 2*sin(x) = 0.

Let's solve that:

2*sin(x) = 1

sin(x) = 1/2.

We know that:

sin(30°) = 1/2.

and

Sin(120°) = 1/2

Then let's convert 30° into radians.

We know that:

pi = 180°.

Then:

pi/180° = 1.

30° = 30°*(pi/180°) = (30°/180°)*pi = (3/18)*pi = pi/6

120° = (120°/180°)*pi = (12/18)*pi = (1/3)*pi = pi/3.

Then the two values of x are: pi/6 and pi/3.

Answer:

5

Step-by-step explanation:

Sent from my iPhone and it is the email address that you sent me

Answer:

C and D.

Step-by-step explanation:

2/6 = 1/3                                    4/12 = 1/3

2/4 = 1/2

2/12 = 1/6

2/24 = 1/12