Find (a) the range and (b) the standard deviation for the given sample

The range is the difference between the highest and lowest value:

Highest value: 85.63

Lowest value : 84.25

Range= 85.63-84.25 = 1.38

Standard deviation:

First, find the mean

Mean = sum of the values / number of values

M = (85.54+84.33+85.15+85.63+84.25+85.18+84.78+85.36+85.04) /9 = 85.03

For each value, subtract the mean and square the result:

85.54-85.03 = 0.51 = 0.51^2 = 0.26

84.33-85.03 = -0.7= 0.49

85.15-85.03 =0.12 = 0.014

85.63-85.03= 0.6 = 0.36

84.25-85.03=-0.78=0.61

85.18-85.03 = 0.15 = 0.02

84.78-85.03=-0.25=0.06

85.36-85.03=0.33 = 0.11

85.04-85.03=0.01 = 0.0001

Calculate the mean of the results ( add results and divide by 9)

1.9241/9=0.21

Square root of that value:

√0.21 = 0.46 (standard deviation)

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w