Answer:
a) 2.0702
b) 2.07
Step-by-step explanation:
Given:
Sample, n = 840
standard deviation, σ = 60
a) The standard deviation of the sampling distribution, will be:
= 2.0702
Standard deviation of the sampling distribution is 2.0702
b) According to the 68 part of the 68-95-99.7 rule, 68% of all values of x fall within 1 standard deviation on either side of the unknown mean μ.
Therefore, missing number will be:
= 1 * 2.0702
= 2.0702 ≈ 2.07
3x + 5 = 23
5 more than(addition) 3 times(multiplication) a variable(x) is(equals) 23
(you add 5 to 3x)
If you need to solve for "x", you need to isolate/get the variable "x" by itself in the equation:
3x + 5 = 23 Subtract 5 on both sides
3x + 5 - 5 = 23 - 5
3x = 18 Divide 3 on both sides to get "x" by itself

x = 6
Answer:
x = 11/10
Step-by-step explanation:
we have from statement:
-1=1 - 4(-5+4x) – 4x
we apply distributive property:
-1 = 1 -4*(-5) -4*(4x) -4x
so we have:
-1= 1+20 -16x -4x
-1 = 21 -20x
-22=-20x
so we have:
x=22/20
x=11/10
we can substitute the x value found:
-1 = 1 - 4(-5+4*(11/10)) – 4*(11/10)
-1 = 1+20 -17.6 -4.4
-1 =21 -22
so we have:
-1 = -1
Area = length x width
area = 2 3/4 x 2/5
area = 1 1/10 feet :)