I’d say 69 i could be wrong tho :) or it is 12 hope this helps
The 69.15 percentile corresponds to 0.500 standard deviations above the mean. If 70 is 10*.500 = 5 units above the mean, then the mean is 65.
Sales $135,000
less: sales returns $3,200
Net sales = $131,800
The answer is c 6+15x+15x
Given: Sound Intensity ( I ) = 
We know, the approximate threshold of human hearing is at 1kHz. In watts/m^2 it's value is
⁻¹² W/m².
So, we can say, Reference sound intensity
= 10⁻¹² W/m².
We have formula for "sound intensity level LI in dB" when entering sound intensity.
LI = 10×log (I / Io) in dB
Plugging values of I and Io in formula.
LI = 10 × log (
)
LI = 10 × log (99000000)
= 10 × 7.99564
LI = 79.96 dB.
Therefore, 79.96 dB is the sound level for a noise that has an intensity of 9.9 × 10-5 watts/m2.