8.9
The equation for the grain size is expressed as the equality:
Nm(M/100)^2 = 2^(n-1)
where
Nm = number of grains per square inch at magnification M.
M = Magnification
n = ASTM grain size number
Let's solve for n, then substitute the known values and calculate.
Nm(M/100)^2 = 2^(n-1)
log(Nm(M/100)^2) = log(2^(n-1))
log(Nm) + 2*log(M/100) = (n-1) * log(2)
(log(Nm) + 2*log(M/100))/log(2) = n-1
(log(Nm) + 2*log(M/100))/log(2) + 1 = n
(log(33) + 2*log(270/100))/log(2) + 1 = n
(1.51851394 + 2*0.431363764)/0.301029996 + 1 = n
(1.51851394 + 0.862727528)/0.301029996 + 1 = n
2.381241468/0.301029996 + 1 = n
7.910312934 + 1 = n
8.910312934 = n
So the ASTM grain size number is 8.9
If you want to calculate the number of grains per square inch, you'd use the
same formula with M equal to 1. So:
Nm(M/100)^2 = 2^(n-1)
Nm(1/100)^2 = 2^(8.9-1)
Nm(1/10000) = 2^7.9
Nm(1/10000) = 238.8564458
Nm = 2388564.458
Or about 2,400,000 grains per square inch.
Subtract 18 from 72 to get Michelle's current age.
72 - 18 = 54
ANSWER:
Total marbles =56
Number of groups =8
Therefore number of marbles in each group =56/8
= 7 marbles in each group.
HOPE IT HELPS!!!!
PLEASE MARK BRAINLIEST !!!!
Answer:
2 Liters
Step-by-step explanation:
.25 liters=1/8 fish aquarium
.25x8=2
Answer: 1.013
Step-by-step explanation:
Given the following data :
X_______f___fx___fx²
1_______15__15___15
2______30__60__120
3______28__84__252
4______10__40___160
______ 83__199__547
Number that is 1.5 standard deviations below the mean :
Mean(m) :
Σfx /Σf
(15 + 30 + 28 + 10) / 83
= 199 / 83
= 2.3976
Standard deviation(s) :
Sqrt[(Σfx² - (Σfx)²/Σf) /Σf-1]
sqrt[(547 - (199)²/83) / 83 - 1]
sqrt[(547 - (39601/83) / 82]
sqrt[(547 - 477.12) / 82]
sqrt(0.8522)
Standard deviation = 0.9231
1.5 standard deviations below the mean:
Mean - 1.5(standard deviation)
2.3976 - 1.5(0.9231)
2.3976 -1.38465
= 1.01295
= 1.013
