In an experimental study, a lab wanted to divide volunteers into two
groups to determine the effect of a particular phone app to help make
people more punctual (on time). The 50 volunteers in the study will be
assigned to either a group of 25 who use the app for a week or a group
of 25 who do not use the app. The participants were asked to come to a
lab to receive the app (or not) at 10:00 am on a Monday. Answer the
following question: Why would those performing the study not want to
assign the participants in the two treatments (groups)based on who
showed up to the study session first? *

Step-by-step explanation:

Assigning the participants based on who shows up first would introduce bias.  Those who arrive first may be more likely to already be punctual.  Giving or not giving them the app may make it seem ineffective when it isn't.

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

answer:

it is 28 degrees colder in detroit than philadelphia.

step-by-step explanation:

what number adds to 21  

-7 + ? = 21

-7 + 28 = 21

hope it