Answer:
19
Step-by-step explanation:
1st you will use a^2+b^2=c^2
next you plug them in so it would be a^2+16^2=25^2
next you would solve it to a^2+256=625
then you would get 369 and square root it
and your answer will be 19.2.
Substitution is best to use one one or both equations is already solved for one of the variables. Elimitation can be use if all variables have a coefficient other than 1.
The sample which is likely to produce the most valid result is Richard's sample because there was no statistical bias. Statistical bias is the systematic favoritism of certain individuals in the study. Just like what Adriana, Henry and Malik did in conducting their surveys, they choose people who are point of interest and also who are near them. In the way Richard conducted his survey, he used a random sampling technique, this is a method of selecting a sample from a population in such a way that every possible individual can be chosen and he doesn't know who these people are.
The answer is 9/5 as 3×3 is 9 and you are dividing it by 5.