9514 1404 393
Explanation:
Divide the figure into areas for which you have a surface area formula. Use the appropriate formula for each area, then add up the results.
Formulas are available for surface areas of a cone, cylinder, sphere, pyramid, rectangular prism, and for plane shapes that are circles, ellipses, triangles, rectangles, trapezoids, and regular polygons.
Most of the figures for which you are asked to find the area will decompose to some subset of these shapes. Take care to identify the relevant dimensions of each of the constituent parts of the area, and to make sure that all parts are accounted for. Do not allow your parts of the area to overlap, unless you intend to account for that overlap by subtracting the area that is counted more than once.
Also, use your common sense. A semicircle will have half the area of a circle, for example.
In some cases, it may be expedient to compute the area of a larger figure than the one you have, then subtract the part of that area that is missing from your figure.
Answer:
r=8
Step-by-step explanation:
Answer:
y = 30 and y = 40
Step-by-step explanation:
All you have to do is add 10 and 12, and see if its is greater than 34. Add the rest of the listed numbers to 12.
Formula for standard deviation sample calculation is:
SD = sqrt (( ∑( x - m)²) / ( n - 1 )),
where x stays for each value in the data set, m stays for mean of all values in the data set, and n stays for the number of values in the data set.
For example: Find the sample standard deviation for the set of numbers: 10, 11, 11, 12, 12.
First we will find mean of all avlues: m = ( 10 + 11 + 11 + 12 +12 ) / 5 = 11.2
SD = sqrt (( 1.2² + 0.2² + 0.2² + 0.8² + 0.8² ) / ( 5 - 1 ))=
= sqrt ( 2.8 / 4 ) = √0.7 = 0.837