"Pneumatic tampers and stronger formwork, as provided nowadays for circumstances in Australia, deserve to reduce the labor input by the variable of 10." just how much percent does "by a element of 10" make?Many many thanks for your help.

You are watching: What does it mean to be off by a factor of 2


*

*

Speaking as an engineer, i would translate "reduce ... Through a aspect of ten" as definition "reduce come one tenth the its original value". The brand-new value would be 10% that the old one, which would be a 90% reduction.

Saying "reduce through 90%" sounds more precise and also has much less emotional impact. "Factor of ten" doesn"t have to mean exactly 10.0.

You"ll periodically hear "order that magnitude" used rather of "factor of ten". Technically, they mean virtually the exact same thing, however in casual speech "order of magnitude " is used figuratively to median "a lot".

EDIT: A lot of of civilization seem to be gaining this wrong, so ns will administer some examples. First, indigenous the Wikipedia short article on orders of magnitude:

An order-of-magnitude difference in between two values is a factor of 10. For example, the massive of the earth Saturn is 95 times that of Earth, for this reason Saturn is two assignment of magnitude an ext massive 보다 Earth. Order-of-magnitude distinctions are called decades when measured on a logarithmic scale.

From HyperPhysics:

...a generally used rule of thumb for sound loudness suggests that one offending sound have to be lessened by a variable of ten in intensity come be decreased to fifty percent as loud.

*

Here"s a more extreme example from a page about gravitational tide detection:

In all, noise is decreased by a factor of ten billion.

Obviously this doesn"t typical that the noise was decreased by 0.00000001%, due to the fact that that would be a ridiculously small difference.

From a web page on chemistry:

Serial dilutions show off diluting a stock or standard solution multiple times in a row. Typically, the dilution aspect remains constant for every dilution, causing an exponential diminish in concentration. Because that example, a ten-fold serial dilution could result in the adhering to concentrations: 1 M, 0.1 M, 0.01 M, 0.001 M, and so on. Together is evidenced in this example, the concentration is reduced by a variable of ten in every step.

From a web page on software program for data backup:

At the worst, we took more 보다 72 hours because that a full back-up ... Through the Quantum solution, a full back-up of our job-related is now completed in eight to ten hours. The moment needed has actually been reduced by a variable of ten.

From a record on trash palliation at take-out restaurants:

At Homeplate, the trash has been reduced by a factor of ten, definition the usual fifty pounds that trash comes from the venue native each enjoy the meal (lunch, dinner) has diminished to a mere five pounds of trash and five pounds the composting.

See more: Top Speed 2006 Suzuki Gsxr 1000 Top Speed ??? 2006 Suzuki Gsxr 1000

I uncovered these by Googling "reduced through a factor of ten" and looking for papers that mentioned particular numbers. In no situation did I discover anything to suggest that reduce by a aspect of ten method a 10% reduction. I have never heard such a usage and will be an extremely surprised if I ever before do.