You proved that failure rate for those 4 Macbooks was exactly 75%. Nothing more, nothing less. Since you're being pedantic, I should point out that he's also p

You proved that failure rate for those 4 Macbooks was exactly 75%. Nothing more, nothing less. Since you're being pedantic, I should point out that he's also proved that the total failure rate is at least three per however-many-Macbooks-there-are.