Erica buys 3.5 pounds of peanut butter. If each pound of peanut butter cost $6.40, how much will she pay for the peanut butter?

Find the total cost

6.40 *3.5 = 22.4$

$22.40

Step-by-step explanation:

1 pound = $6.40

3.5 lb. x $6.40 = $22.40

to check:

$22.40 total ÷ 3.5 pounds = $6.40 per pound

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

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