The historian of a town with about 1900 households conducts a study to determine the average number of years each family has lived in the town. He randomly selects 1012 addresses from property records and observes a mean of 21.2 years and a standard deviation of 5.1 years of residency for those households. A histogram of the data shows a roughly symmetric curve with one peak. The historian cannot use our procedures to conduct inference on the mean number of years residents have lived in this town because the is too large for this population.

a negative exponent is translated as follows:

so, we have

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

could you provide figure.