Answer:

perform cross multiplication:

First you need to know that the internal angles of a triangle always equals 180°. Therefore:
15+45= 90°
Then since the angles should equal 180, you do:
180-90=90
So the missing angle equals 90°
Answer:
The scatter diagram that contains the correlation coefficient closest to r = 1 is the first one shown in the attached images.
Step-by-step explanation:
The correlation coefficient "r" measures how much two variables x and y are related. When the variables are highly related, the value of r is closer to one and the points contained in the scatter diagrams are assimilated more and more to a line. When the value of r is positive the relation is crescent and therefore the slope of the line drawn by the points in the diagram has a positive slope
Therefore, to answer this question, one must search among the attached images for the dispersion diagram in which the points resemble a straight line with a positive slope.
The scatter diagram that meets the requirements mentioned is the first one that appears in the attached images