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?

Answers

Answer 1

Answer:

C this is a double blind study.

Step-by-step explanation:

Both groups in the experiment are blind (don't know they are in an experiment). If this answer is incorrect then its A.

Answer 2

Answer:

observational study

Step-by-step explanation:
the experimenters are not blind to their own tests.


Related Questions

Please I need help thank you

Answers

40 students because you already divided it and it’s estimated

Answer:

its 40

Step-by-step explanation:

You've already divided 320 and 8 and you get 40

what is the equation of the line in slop-intercept form​ HELPP PLZZZZZZZZZZ

Answers

Answer:

y = 3/5x + 3

Step-by-step explanation:

(y2-y1)/(x2-x1) = slope

pick 2 points (0,3) and (-5,0)

(0-3)/(-5-0) = -3/-5 = 3/5

y = 3/5x + b

3 = 3/5(0) + b, b = 3

equation y = 3/5x + 3

4.
It takes a lady 3 days to wash the windows
inside and out. Her husband can do the job
in 4 days. How fast can they do it together?

Answers

1/tb = 1/t1 + 1/t2
1/tb = 1/3 + 1/4
1/tb = 4/12 + 3/12
7/12 flip reciprocal = 12/7
It takes them 1.71 days

20. John Navarro is a salesperson in the appliance department at Morris

Appliance, Inc. He is guaranteed a minimum salary of $185 per week, or

5.5 percent of his total sales—whichever is greater. What is his gross pay

for a week in which his total sales were $3,422?

Answers

Answer:

$373.21

Step-by-step explanation:

Step one:

weekly pay = $185

commission= 5.5% of sales= 0.055

let the sale be x

and his gross pay be represented by y

hence the expression for the total/gross pay is

y=0.055x+185

Step two:

Required is the gross pay y for x=3422

substituting we have

y=0.055*3422+185

y=188.21+185

y=373.21

Hence for a sale of $3,422 made his gross pay is $373.21

If a bug can flap its wings at a rate of 77 times in 9 seconds, how many times do they flap their wings in 1.119 minutes? Round to 1 decimal.

Answers

I believe it is 957.4

In a certain company a salesman is paid a fixed salary for $3140 per month plus an annual commision of 2% on the TOTAL value of cars sold for the year. If the salesman sold cars valued at $720000 in 2009 calculate:
(i) his fixed salary for the year

(ii) the amount he recieved in commision for the year

(iii) his TOTAL income for the year​

Answers

Step-by-step explanation:

(i) 12 months × fixed salary

= 12 × 3140

= 37680 $

(ii) commission = total × 2%

= 720000 × 0.02

= 14400 $

(iii) fixed salary + commission

= 37680 + 14400 = 52080 $

if two dice are rolled one time, find the probability of getting a sum less than or equal to 4 ​

Answers

Answer:

The probability of getting a sum less than or equal to 4 ​is 1/6.

Step-by-step explanation:

When two dices are rolled, the number of outcomes are: 6*6 = 36 which is written in ordered pairs consisting of outcome of both dices.

When two dices are rolled, the number of sample space elements is:

[tex]n(S) = 36[/tex]

Let A be the event that the sum of outcomes is less than or equal to 4:

[tex]A = \{(1,1),(1,2),(1,3),(2,1),(2,2),(3,1)\}[/tex]

That implies

[tex]n(A) = 6[/tex]

The probability of getting sum less than or equal to 4 will be:

[tex]P(A) = \frac{n(A)}{n(S)} = \frac{6}{36} = \frac{1}{6}[/tex]

Hence,

The probability of getting a sum less than or equal to 4 ​is 1/6

The probability of getting a sum less than as well as equivalent to 4 will be "[tex]\frac{1}{6}[/tex]".

Probability:

The probability that may be an outcome will happen together in random experiment. The greater the likelihood of such an occurrence, the further probable it will materialize.

Let,

The event that the sum less than as well as equivalent to 4 be "A".

According to the question,

Whenever the 2 dices are rolled, the no. of outcomes will be:

= 6 × 6

= 36

and,

The no. of sample elements will be:

n(S) = 36

Now,

A = {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (3, 1)}

The probability be:

P(A) = [tex]\frac{n(A)}{n(S)}[/tex]

           = [tex]\frac{6}{36}[/tex]

           = [tex]\frac{1}{6}[/tex]

Thus the response above is correct.

Find out more information about probability here:

https://brainly.com/question/24756209

y = 12 • 3x for x = –2

Answers

Answer:

y=-72

Step-by-step explanation:

3(-2) = -6, y=12 times -6, y= -72

heidi subtract 9 from 17. first she adds to get 10.then she added again to find her answer is heidi correct Heidi is not correct to add blank then you add blank more to get 10 to 17 the answer is

Answers

Answer:

Heidi wants to compute:

17 - 9.

First, she adds to get 10, (we want to subtract 10, this is easier than subtracting 9) then she can do:

17 - 9 + 0

adding zero does not change the sum

1 - 1 = 0

then:

17 - 9 + 0 = 17 - 9 + 1 - 1

Now we can do:

17 - 9 - 1 + 1

17 - (9 + 1) + 1

17 - 10 + 1

(17 - 10) + 1

7 + 1 = 8

Then, first she needs to add -1, in order to subtract 10, and then she must add 1. As we added a number and its inverse, in total we added zero, so the sum did not change, but was easier to compute.

Then, you need

A communications tower is supported by two wires, connected at the same point on the ground. One is attached to the tower at D and the long-on at C. The angle AD makes with the ground is 30 ° and the angle between the two wires is 10 °. How much below the top of the tower is the shorter one attached?

Answers

Answer:

10.99 m

Step-by-step explanation:

✍️What we are basically asked to solve here is to find the distance between C and D.

To find CD, find the length of BC, and BD. Their difference will give us CD.

Thus, BC - BD = CD.

✍️Finding BC using trigonometric ratio formula:

[tex] \theta = 30 + 10 = 40 [/tex]

Opposite side = BC = ??

Adjacent side = 42 m

Thus:

[tex] tan(\theta) = \frac{opposite}{adjacent} [/tex]

Plug in the values

[tex] tan(40) = \frac{BC}{42} [/tex]

Multiply both sides by 42

[tex] tan(40) \times 42 = \frac{BC}{42} \times 42 [/tex]

[tex] 35.24 = BC [/tex]

BC = 35.24 m

✍️Finding BD using trigonometric ratio formula:

[tex] \theta = 30 [/tex]

Opposite side = BD = ??

Adjacent side = 42 m

Thus:

[tex] tan(\theta) = \frac{opposite}{adjacent} [/tex]

Plug in the values

[tex] tan(30) = \frac{BD}{42} [/tex]

Multiply both sides by 42

[tex] tan(30) \times 42 = \frac{BD}{42} \times 42 [/tex]

[tex] 24.25 = BD [/tex]

BD = 24.25 m

✍️How much below the top of the tower is the shorter one attached:

Thus,

BC - BD = CD

35.24 m - 24.25 m = 10.99 m

simplify the following square root √ -1 =​

Answers

Answer:

1 .

because sqare root of -1= 1

Answer:

It is Undefined, as a negative square root does not contain real numbers. Or in other words it doesn’t have anything to simplify to.

1. Alison has 3 skirts, 2 shirts, and 2 pairs of shoes. How many different combinations of
skirt, shirt, and shoes can she choose?

Answers

Answer:

12

Step-by-step explanation:

3x2x2 or make a tree diagram

consider the equation x-y=-1 ..calculate the value of y if x =1​

Answers

Answer:

y = 2

Step-by-step explanation:

For the equation x - y = -1, if x = 1,

then we would plug that in to solve for the y value

1 - y = -1

Subtract 1 from both sides to find y

-y = - 2

Divide by -1 to find y

y = 2.

To double check our answer we would plug in our x-value and y-value into the equation

1 - 2 = -1

This is true, so our answer is y = 2

Answer:

y = 2

Step-by-step explanation:

x - y = -1

1 - y = -1

1 + 1 - y = 0

2 - y = 0

2 = y

y = 2

What is the quotient of
3/4 and 1/5

Answers

Answer:

3.75

Step-by-step explanation:

Gail collects trading cards. Her favorites are baseball and football cards. For
every 10 baseball cards she owns, Gail has 17 football cards. What is the
ratio of baseball cards to football cards in her collection?
O A. 17:10
B. 10 and 17
O c. 12
O D. 17 to 10

Answers

I think it’s c but don’t go with me see if others answer with a different answer :)

Step-by-step explanation:

its ratio so it has to be A

P and q are integers that are multiple of 5. Which of this

not true about p and q

(a) P + q is divisible by 5

(b) P –q is divisible by 10

(c) P + q is divisible by 20

(d) P + q is divisible by 25​

Answers

Answer:

we conclude that the only option (a) is true.

Step-by-step explanation:

As we know that the multiples of 5 are the numbers which we get when we multiply by 5.

i.e.

5×1=5

5×2=10

Here, 5 and 10 are multiples of 5.

Let p and q are integers that are multiples of 5.

Let us consider

p=5

q=10

so

p+q=5+10

     = 15

A number is divisible by 5 if it ends in 5 or 0.

i.e. 15/5 = 3

so p+q is divisible by 3 as there is no remainder left.

Therefore, option (a) is true.

Checking the other options:

(b) P –q is divisible by 10

As

p=5

q=10

so

p-q=5-10

     = -5

Numbers that are divisible by 10 need to be even or divisible by 2 and divisible by 5.

As -5 is not divisible by 2.

So, option b is NOT true.

(c) P +q is divisible by 20

As

p=5

q=10

so

p-q=5+10

     = 15

Divisibility rule of  20  implies that the last two digits of the number are either  00  or divisible by  20 .

Therefore, P + q= 20 is not divisible by 20 as we don't get the whole number.

(d) P + q is divisible by 25​

As

p=5

q=10

so

p-q=5+10

     = 15

p+q=15 is not divisible by 25 as it does not end with 00, 25, 50, or 75.

so, option d is NOT correct.

Therefore, we conclude that the only option (a) is true.

Re-write the equation in slope-intercept form: 5x + 4y = 20

Answers

Answer:

y=5-5/4x

Step-by-step explanation:

slope-intercept form:   y=mx+b (m= slope, b= y-intercept)

5x + 4y = 20

4y=20-5x

simplify

y=5-5/4x

A line contains the points A, B, C, and D. Point B is
between points A and C. Point D is between points C
and B. Which of the following inequalities must be true
about the lengths of these segments?
F. BC < AB
G. BD < AB
H. BD < CD
J. CD < AB
K. CD

Answers

Answer:

a

Step-by-step explanation:

aa

A square has a side length 9 cm. What is its area? A square has an area of 9 cm2. What is its side length?

Answers

Answer:

Area = 81; Side Length = 3

Step-by-step explanation:

The area of a square is the side lenght squared, and 9² is 81.

The side lengh can be found by taking the square root of the area. √9 = 3

x^2+8x=0

what is the sum of the solutions? please help me!!​

Answers

Answer:

Step-by-step explanation:

0

,

8

/

Which statement is false?

A.
by SSS
B.
by SAS
C.
by SAS
D.

Answers

Answer:

sorry, i haven't understood your question!! how can i tell which statement is false.

Seema deposited $800 in a saving account earning 2.88% compounded annually. To the nearest cent, how much will she have in 16 years? Do not include the dollar sign in your answer.​

Answers

Answer:

1260.04

Step-by-step explanation:

The formula for compound interest is:

A = P(1+[tex]\frac{r}{n}[/tex][tex])^{nt}[/tex] where A is the final amount, P is the initial principal balance, r is the interest rate, n is the number of times interest applied per time period and t is the number of time periods elapsed. Since the deposit was compounded annually, just like the interest, we can omit the n in the equation.

Applying the formula to question:

800(1+[tex]\frac{2.88}{100}[/tex][tex])^{16}[/tex] = 1260.04 (rounded off to nearest cent since it's money)

3. You receive an order for 0.5 g of Tigan IM. You have a 5 mL vial labeled 100 mg/mL. What is the
volume you will need to fill the order?
a. 2 mL
c. 0.5 mL
b. 5 mL
d. 0.02 mL

Answers

Answer:

52

Step-by-step explanation:

find gcd of (510,92)​

Answers

Answer:

The GCD of 510 and 92 is 2

Step-by-step explanation:

510 : 2 = 255

510 : 3 = 170

510 : 4 = 127.5

92 : 2 = 46

92 : 3 = 30.6667

92 : 4 = 23

hope this helps!

What is the sign of the product (–5)(–3)(–8)(–6)? Positive, because the products (–5)(–3) and (–8)(–6) are negative, and the product of two negative numbers is positive Positive, because the products (–5)(–3) and (–8)(–6) are positive, and the product of two positive numbers is positive Negative, because the products (–5)(–3) and (–8)(–6) are negative, and the product of two negative numbers is negative Negative, because the products (–5)(–3) and (–8)(–6) are positive, and the product of two positive numbers is negativeWhat is the sign of the product (–5)(–3)(–8)(–6)? Positive, because the products (–5)(–3) and (–8)(–6) are negative, and the product of two negative numbers is positive Positive, because the products (–5)(–3) and (–8)(–6) are positive, and the product of two positive numbers is positive Negative, because the products (–5)(–3) and (–8)(–6) are negative, and the product of two negative numbers is negative Negative, because the products (–5)(–3) and (–8)(–6) are positive, and the product of two positive numbers is negative

Answers

Answer:

The sign is positive.

Step-by-step explanation:

(-5)(-3)

= 15 (double negative)

15(-8)

=-120 (positive negative)

(-120)(-6)

= 720 (negative negative)

Therefore, the sign of the answer is positive.

Hope this helped!

Answer:

The sign is postive

Step-by-step explanation:

(-5)(-3)

= 15 (double negative)

15(-8)

=-120 (positive negative)

(-120)(-6)

= 720 (negative negative)

Mason Crosby kicked a career long 61 yard field goal. How many feet did the ball travel?

Answers

Answer:

fgqwefgwdgnbn8jhvdsihijhofwebhiwg7dyhdg h hy7rhbfwe  r2eery

Step-by-step explanation:

sdheeht vuhudfvbujhnrsdgbkbhdpouibeihbrtuiovb esg7veg8sgxvuew hr 8b0uw e

Find the value of P for which the inflows will equal the outflows. Find the effective rate first.


Rate 8% p y c d
Year Outflows Inflows
0 -P
1 -2P
2 -4P
3 -8P
4 -16P
5 $24,000
6 $30,000
7 $36,000
8 $42,000
9 $48,000
10 $54,000

Answers

Answer:

The answer is "p= $5,246".

Step-by-step explanation:

Using formula:

Present value of [tex]\frac{in-flow}{out-flow}[/tex] = cash-flow [tex]\times[/tex] present value of discounting factor(rate %, time period)

[tex]\to -p-\frac{2p}{1.08}-\frac{4p}{1.08^2}- \frac{8p}{1.08^3}-\frac{16p}{1.08^4} =\frac{24000}{1.08^5}+ \frac{30000}{1.08^6}+ \frac{36000}{1.08^7} + \frac{42000}{1.08^8}+ \frac{48000}{1.08^9}+ \frac{24000}{1.08^{10}}\\\\[/tex]

[tex]\to -p[1+\frac{2}{1.08}+\frac{4}{1.08^2}+ \frac{8}{1.08^3}+\frac{16}{1.08^4}] = 127960.43169\\\\\to -p[24.3923427] = 127960.43169\\\\\to -p = \frac{127960.43169}{24.3923427}\\\\\to p= 5245.93\\\\\to p= 5246[/tex]

Can a quadratic have one real and one non real root

Answers

Answer:

Yes, it is possible. We already know that complex roots exist in conjugate pair but the case is true only when the equation has real coefficients. But on the other hand, if the equation has complex coefficients, then it is possible to attain one real and one complex root.

Determine the domain of the function graphed above.

Answers

Answer:

Domain: (-∞, ∞)

General Formulas and Concepts:

Algebra I

Domain is the set of x-values that can be inputted into function f(x)

Step-by-step explanation:

According the the graph, we see that our x-values are spanning forever in both directions. Therefore our domain is:

(-∞, ∞) or -∞ < x < ∞

(25)2 × 100 ÷ 23 + [24 ÷ (13 – 5)] =

Answers

Answer:

It may be 220 9/23. If it's wrong sorry lol.

Step-by-step explanation:

I- uhhhhhhhhhh dkkkkk
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