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.
Answer:
1 a
2 b
3 c
4 d
Step-by-step explanation:
1b
2d
3c
4a
The volume of any prism is given by
.. V = Bh . . . . B is the area of the base, h is the height
You have
.. 300 = B*3
.. 300/3 = B = 100
The area of the base is 100 square units.
Answer:
m + n = 15
m - 3 = n
The numbers are 9 and 6
Step-by-step explanation:
From the question,
The sum of two numbers is fifteen; the first number is m and the second number is n. To translate to a system of equations, we can write that
m + n = 15 ..... (1)
Also, from the question,
One number is three less than the other,
Also, to translate to a system of equations, we can write that
m - 3 = n ...... (2)
If desired, we can determine m and n
From equation (1)
m + n = 15
Then,
m = 15 - n ...... (3)
Put the value of m in equation (3) into equation (2)
m - 3 = n
Then
15 - n - 3 = n
15 - 3 = n + n
12 = 2n
n = 12/2
∴ n = 6
For m, put the value of n into equation 3
m = 15 - n
m = 15 - 6
m = 9
∴ m = 9 and n = 6
Hence, the numbers are 9 and 6
