Which statement is true about the difference of the sample means? o The difference of the sample means is statistically significant because it falls
within the 5% significance level.
o The difference of the sample means is not statistically significant because it
falls outside the 5% significance level.
o The difference of the sample means is not statistically significant because it
falls within the 5% significance level.
o The difference of the sample means is statistically significant because it falls
outside the 5% significance level.

for b its (t) and c its (d)

step-by-step explanation:

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

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".