To write a number in scientific notation, you need to write the number as a product of a number from 1 to under 10 multiplied by a integer power of 10.
First, what number from 1 to under 10 can you get out of the digits of 150,000,000 just by changing the decimal point? The answer is 1.5 since 1.5 is greater than or equal to 1 and less than 10.
150,000,000 = 1.5 * 100,000,000
Now we change 100,000,000 into a power of 10. A 1 followed by a number of zeros is the same as 10 to the power equal to the number of zeros. In 100,000,000 the 1 is followed by 8 zeros, so 100,000,000 = 10^8.
150,000,000 = 1.5 * 10^8
The data given as a whole would be called ungrouped data. Now to get the variance, you will need the formula:
s^2= <u>Σ(x-mean)^2</u>
n
x = raw data
mean = average of all data
n = no. of observations
s^2 = variance
Now we do not have the mean yet, so you have to solve for it. All you need to do is add up all the data and divide it by the number of observations.
Data: <span>90, 75, 72, 88, 85 n= 5
</span>Mean=<u>Σx</u>
n
Mean = <u>90+75+72+88+85 </u> = <u>410</u> = 82
5 5
The mean is 82. Now we can make a table using this.
The firs column will be your raw data or x, the second column will be your mean and the third will be the difference between the raw data and the mean and the fourth column will be the difference raised to two.
90-82 = 8
8^2 =64
75-82 = -7
-7^2 =49
72-82 = -10
-10^2=100
88-82=6
6^2 = 12
85-82=3
3^2=9
Now you have your results, you can now tabulate the data:
x mean x-mean (x-mean)^2
90 82 8 64
75 82 -7 49
72 82 -10 100
88 82 6 36
85 82 3 9
Now that you have a table, you will need the sum of (x-mean)^2 because the sigma sign Σ in statistics, means "the sum of."
64+49+100+36+9 = 258
This will be the answer to your question. The value of the numerator of the calculation will be 258.
<u>
</u>
Zero.
Anything times zero is zero.
-20 * -10 = 200
200 * -1 = -200
-200 * 0 = 0
