Paired t-tests are a form of blocking, and have greater power than unpaired tests when the paired units are similar with respect to noise factors that are independent of membership in the two groups being compared.
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AOL's Silicon Valley branch office. AOL is an internet company founded in 1985 as Quantum Computing Services. Each acquisition is for the respective company in its entirety. The acquisition date listed is the date of the agreement between AOL and the subject of the acquisition. The value of each acquisition is listed in US dollars because AOL is headquartered in the United States. If the value of an acquisition is not listed, then it is undisclosed. As of August 2013, AOL's largest acquisition has been the purchase of Netscape, a web browser company, for US$4.2 billion.