Answer:
Step-by-step explanation:
-6+(-3)
-6-3
Answer is -9
Answer:
I dont speak English so I can't help anyone
If they don't intersect then there is no solution and the lines are parrell.
Answer:
First statement is correct.
Step-by-step explanation:
If we add or subtract a constant to each term in a set: Mean will increase or decrease by the same constant. Standard Deviation will not change.
If we increase or decrease each term in a set by the same percent (multiply all terms by the constant): Mean will increase or decrease by the same percent. Standard Deviation will increase or decrease by the same percent.
For example:
Standard Deviation of a set: {1,1,4} will be the same as that of {5,5,8} as second set is obtained by adding 4 to each term of the first set.
That's because Standard Deviation shows how much variation there is from the mean. And when adding or subtracting a constant to each term we are shifting the mean of the set by this constant (mean will increase or decrease by the same constant) but the variation from the mean remains the same as all terms are also shifted by the same constant.
So according to this rule, statement (1) is sufficient to get new Standard Deviation, it'll be 30% less than the old.. As for statement (2) it's clearly insufficient as knowing mean gives us no help in getting new Standard Deviation.
