1. Hoover Dam spans the Colorado
River on the Nevada-Arizona state
line. For its construction, the federal
government purchased 21,670,000
pounds of gates and valves. Which
number is the BEST estimate of this
amount?
A. 2 x 10^7
B. 2 x 10^8
C. 3 x 10^7
D. 3 x 10^8

BEST estimate of this  amount is . Correct option A. 2 x 10^7 .

Step-by-step explanation:

Here we have , Hoover Dam spans the Colorado  River on the Nevada-Arizona state  line. For its construction, the federal  government purchased 21,670,000  pounds of gates and valves. We need to find BEST estimate of this  amount . Let's find out:

21,670,000  pounds

⇒ 21,670,000  pounds

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⇒

⇒

⇒

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Now, Rounding of 2.167 we get 2  ,So

⇒

Hence ,  BEST estimate of this  amount is . Correct option A. 2 x 10^7 .

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart