Need Help with a percentage question

[neilm]

Okay, this is for a construction project and I cant figure out the number. For clarity, we are to test 4 bars per lot. A lot is 100 bars. That is simple. However, it goes on to say that after 3 lots, if there are no failures then test at a rate of 2%. If after another 3 lots there are no failures test at a rate of 1% for the remaining lots.

If a lot is equal to 100 bars and I test 4 bars per lot, what would be the 2% and 1% rate?

 

[girodd]

it probably means 2% or 1% of a lot, i.e., 2 bars or 1 bar per lot

 

[neilm]

it probably means 2% or 1% of a lot, i.e., 2 bars or 1 bar per lot

Yeah, that is kind of what I thought, but the verbiage is very tricky. I would interpret it as "If the frequency rate of 100% testing is 4/100, then 2% of that rate is 0.08 bars per lot." Of course, how do you sample 8% of one bar?

 

[JeffM]

Yeah, that is kind of what I thought, but the verbiage is very tricky. I would interpret it as "If the frequency rate of 100% testing is 4/100, then 2% of that rate is 0.08 bars per lot." Of course, how do you sample 8% of one bar?

I agree the wording is not perfectly clear, but 2% of a rate is sort of a sophisticated concept. That is, how many people do you know who would say that they were travelling at 60% of 60 miles per hour to mean traveling at 36 miles per hour. You may have been overthinking this one.

 

[HallsofIvy]

Okay, this is for a construction project and I cant figure out the number. For clarity, we are to test 4 bars per lot. A lot is 100 bars.

So 4 bars out of a lot of 100 bars is 4%.

That is simple. However, it goes on to say that after 3 lots, if there are no failures then test at a rate of 2%.

Assuming there are still 100 bars per lot, 2% of 100 is 2 bars.

If after another 3 lots there are no failures test at a rate of 1% for the remaining lots.

1% of 100 bars is 1 bar per lot.

If a lot is equal to 100 bars and I test 4 bars per lot, what would be the 2% and 1% rate?

In other words, for the first three lots you test 4 bars of each lot (a total of 12 bars). If there are no failures, you start testing 2 bars per lot. If, after another three lots, so 6 bars, for a total of 12+ 6= 18 bars, there are no failures, you start testing just one bar per lot. I presume that if you ever do get a failure you would go back to testing four bars per lot.