Answer: The answer is 8.
Step-by-step explanation: The first step is to convert the expression into figures. We shall call the unknown number Y. So if we are told “the square of a number,” that means Y squared, or better still, Y^2. Further we are told “the difference between the square of a number and 40” and that can be written as;
Y^2 - 40.
Next we are told that this expression is equal to 3 times that number (that is 3Y). That can now be written out as follows,
Y^2 - 40 = 3Y
If we move all expressions to one side of the equation, what we would have is,
Y^2 - 3Y -40 = 0
(Remember that when a positive value crosses to the other side of an equation it becomes negative and vice versa)
We now have a quadratic equation
Y^2 -3Y - 40 = 0
By factorizing we now have
(Y -8) (Y + 5) = 0
Therefore Y - 8 = 0 or
Y + 5 = 0
Hence, Y = 8 or Y = -5
Since we are asked to calculate the positive solution, Y = 8
Answer:
12. 524 in³ (3 sig. fig.) 13. 2000 cm³ (3 sig. fig.)
Step-by-step explanation:
12. Volume of sphere = (4/3)πr³
= 500/3π
= 524 in³ (3 sig. fig.)
13. Volume of cylinder = πr²h
= 7²π(13)
= 637π
= 2000 cm³ (3 sig. fig.)
Answer:
It would take Brennan 4 track practice runs.
Step-by-step explanation:
He has already run 16 miles and needs to run 28 in total. If we are counting the 16 in the 28 miles, he would need to run only 12 more to reach his goal. And if he runs 3 miles a run, it would take him about 4 runs to finish his 28-mile goal.
(28-16=12 and 12/3=4)
Answer:
Sampling bias
Step-by-step explanation:
Bias refers a prominent problem in statistical analysis whereby one or more analytical factor are favored than the other during an analysis which should be made random. The problem. With Graham's dissertation study is the fact that he failed to randomlyvplace his subjects or observation in the study groups, favoring a particular group with non random subset. When randomization is ejected or missing from an analysis or study, it becomes less and less representative. Here, allotting early Arrivals Into the treatment group has introduced a sampling bias as those who came later, this will also leads to less reproducibility of experiment.
