What the standard deviation really tells you is that some set of users were + or - the test average (or arithmetic mean).

标准偏差真正能够告诉您的是，某些用户是高于还是低于平均测试水平(或者算术含义)。

youdao

Over half of Mexican 15-year olds were classed as incapable of doing basic arithmetic on the maths portion of the test.

在墨西哥15多岁的少年中，超过1/2的人员在测试中的数学部分被划分为不会做基 础算术。

youdao

The device, which consists of two conductors fastened to the head by a rubber strap, significantly boosted results in a simple arithmetic test, they said.

这些科学家说，这个设备由两块导体组成，由一个橡胶带夹在头两侧，在一次简单的计算测试中能明显的提高成绩。

youdao

Psychologists had 543 men and women in a mall, ages 25 to 75, take a test that involved quickly evaluating whether a series of arithmetic problems had been properly solved.

WSJ: Swearing Off Pain, Age and Competition, a 16-Foot Emoticon | Week in Ideas

But 76% agreed with proposals to test the skills of trainee teachers in the areas of reading, writing, arithmetic and new technology.

BBC: Teachers 'reject payment by results'