Supported i’m pretty sure. Not much background to the problem though.
Explanation : x = 79 marks
The marks scored by Mike on four math test are 88,91,75 and 72.
Average of marks, A = 81
Let in fifth test he scores x marks.
The formula for finding average is :




In the fifth test he scores 79 marks.
Hence, this is the required solution.
Answer:
pH meter and pH paper.
Explanation:
There are a few other ways that are commonly used, including titration, but most are tedious and require detailed hands-on work. A pH meter is normally assisted by the use of a computer or a digital user interface. The use of pH paper can be likened to the use of a Galileo thermometer.
As means of locomotion, bacteria possess flagella.
The reason for the loss of color after the industrial revolution is that the light-colored moths were "selected against" by predators. These birds could only see the light ones against the newly dark, sooted background. Over time, these predators could no longer distinguish the dark ones from their natural dark, sooted background. Thus more light-colored moths stood out against the dark soot, and were eaten. And more dark-colored moths eluded the birds, survived to reproduce, passing on more of their dominant genes for dark color to their offspring. After several decades of hundreds of thousands of generations, most of the later generations were dark, due to selective advantage of camouflage to survive predation.