Final answer:
The total magnification when viewing with a 40x objective lens and a standard 10x ocular lens on a microscope is 400x.
Step-by-step explanation:
When viewing bacteria with a microscope using a 40x objective lens and a standard ocular lens, which typically has a magnification of 10x, the actual magnification at which you are viewing the specimen is calculated by multiplying the magnification of the objective lens by the magnification of the ocular lens. Therefore, the total magnification would be 400x (40x objective lens multiplied by 10x ocular lens).
The actual magnification you are viewing the specimen at with a 40x objective on a microscope is 400x. This is calculated by multiplying the magnification of the objective lens (40x) by the magnification of the ocular lens (10x). So, 40x multiplied by 10x equals 400x.