Question

a jellyfish found in australia and a spider found in brazil are two of the most venomous animals in the world. a researcher recorded the size of the jellyfish as 3.472×10^(-4) cubic feet. the researcher also recorded the size of the spider as 3.09×10^(-3) cubic feet. what is the difference between the size of the spider and the size of the jellyfish, expressed using significant digits? 3.06×10^(-3) cubic feet 3.82×10^(-3) cubic feet 3.82×10^(-7) cubic feet 0.56×10^(-8) cubic feet

Explanation:

Step1: Identify the sizes

Size of spider $a = 3.09\times 10^{-3}$ cubic - feet, size of jelly - fish $b = 3.472\times 10^{-7}$ cubic - feet.

Step2: Calculate the difference

We want to find $a - b$. First, rewrite the numbers with the same exponent. $3.09\times 10^{-3}=30900\times 10^{-7}$. Then $a - b=(30900\times 10^{-7})-(3.472\times 10^{-7})=(30900 - 3.472)\times 10^{-7}=30896.528\times 10^{-7}=3.0896528\times 10^{-3}\approx3.09\times 10^{-3}$ (using significant digits).

Answer:

$3.09\times 10^{-3}$ cubic feet