Answer: The first study was an observational study whereas the second was a controlled experiment.
Step-by-step explanation:
A study that record the characteristics of a population by studying individuals in a sample, but does not manipulate variables of interest is known as an operational study. Like in the first study only effects have been noted.
A controlled experiment is an experiment where the variable of interest is directly manipulated by a scientist, in order to test a single variable at a time.
Like in the second study, the subjects were under the control of the experimenter, to test the effect of oil.
The first study was an observational study whereas the second was a controlled experiment.
.76 as a fraction in simplest form is 19/25.
Answer:
-3.5
Step-by-step explanation:
An example is -3.5.
<h2>○=> <u>Correct options</u> :</h2><h2>□

</h2><h2>□

</h2><h3><u>Steps to derive the correct options</u> :</h3>
Since two sides and one included angle is equal in △PQS and △PRS, we can conclude that they are congruent under the SAS congruence criterion.
Which means :
▪︎Angle S = Angle S
▪︎PS = PS
▪︎QS = RS
Given :
Measure of segment QS = 6n+3
Measure of segment RS = 4n+11
Thus :







Thus, the value of n = 4
Measure of segment QS :




Thus, measure of QS = 27
Measure of RS :




Measure of QR :


Thus :
▪︎QS = 27
▪︎RS = 27
▪︎QR = 54
Therefore, the correct options are :
▪︎(C) SR = 27
▪︎(D) QR = 54