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Dmitriy789 [7]
3 years ago
14

A medical researcher studies the correlation between the number of hours spent at office jobs and the incidence of chronic back

ache. Which statement BEST describes why the investigation is an observational study?
A) The researcher does not use a control group.
B) The researcher does not intervene to vary conditions.
C) It is not possible to obtain a random sample of office workers.
D) It is not possible to establish a cause-effect relation between the variables.
Mathematics
1 answer:
Sati [7]3 years ago
5 0
The answer for this question is C 

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stira [4]
Well....if the triangle shape stays the same then the angle stays the same even if its enlarged in size. It will stay the same because you didn't change the way the shpae looks like, it is just zoomed in.

Answer: The angle measurements stay the same when the figure is enlarged or reduced
5 0
3 years ago
Using the digits 2 through 8, find the number of different 5-digit numbers such that, digits can be used more than once.
Solnce55 [7]

Answer:

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7 0
3 years ago
Can anyone pls helppppp
dalvyx [7]
Hourly rate:
39(1.3r) = 541.80
(hours times hourly rate equals profit)

then solve
1.3r = 13.89
r = 10.69

the hourly rate is $10.69


to answer the bottom question, 390 + 117 = 507, but that’s not close to 541.80 so I have no idea what they’re asking there
4 0
3 years ago
Referring to the Fig. in Question #40, find the unknown<br> length Y.
icang [17]

Answer:

tan30°=7/x

\frac{1}{ \sqrt{3} }  =  \frac{7}{x }  \\ x = 7 \sqrt{3}

cos30°=x/y

\frac{ \sqrt{3} }{2}   =  \frac{7 \sqrt{3} }{y}  \\  \\ 7 \sqrt{3}  \times 2 =  \sqrt{3}  \times y \\ \frac{7 \sqrt{3 }  \times 2}{ \sqrt{3} }  = y \\7 \times 2 = y \\ 14 = y

tell me if it's wrong.

7 0
2 years ago
Read 2 more answers
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