An environmental scientist tested a compost sample in the lab to find the number of bacteria it contained. The following output was given on her machine for one gram of compost.

Question

1.1E9

The mass of one cubic yard is about 765,000 grams. About how many bacteria would she expect to find in a cubic yard of the same compost?
A.
8.415 × 1015
B.
8.415 × 1014
C.
8.415 × 1013
D.
8.415 × 1012

Answer 1

To estimate the total number of bacteria in a cubic yard of compost, we can follow these steps:

1. Determine the number of bacteria in one gram of compost: The output indicates that there are 1.1 × 10^9 bacteria in one gram of compost.

2. Determine the mass of a cubic yard in grams: We know that one cubic yard is about 765,000 grams.

3. Calculate the total number of bacteria in one cubic yard by multiplying the number of bacteria in one gram by the total mass of the cubic yard: \[ \text{Total Bacteria} = (1.1 \times 10^9 \text{ bacteria/gram}) \times (765,000 \text{ grams}) \] \[ = (1.1 \times 10^9) \times (7.65 \times 10^5) \] \[ = 1.1 \times 7.65 \times 10^{9 + 5} \] \[ = 8.415 \times 10^{14} \text{ bacteria} \]

So, the answer is: B. 8.415 × 10^14.