Answer:
5.1 days
Step-by-step explanation:
Given in the question,
initial amount of substance = 34 grams
k-value = 0.137
To find the half life of this substance we will use following formula
here N(0) is initial amount of substance
t is time in days
Plug values in the formula
1/2 = e^{-0.137t}
Take logarithm on both sides
ln(1/2) = ln( e^{-0.137t})
ln(1/2) = -0.137t
t = ln(1/2) / -0.137
t = 5.059
t ≈ 5.1 days (nearest to tenths)
Answer:
Modification has not reduced the number of accidents.
Step-by-step explanation:
A B C D E F G H
Before modification 5 7 6 4 8 9 8 10
After modification 3 7 7 0 4 6 8 2
Difference -2 0 1 -4 -4 -3 0 -8
Mean of differences
Standard deviation of differences =
Formula of paired t test :
Df = n-1 = 8-1 =7
t critical> t calculated
So, We failed to reject null hypothesis
Hence modification has not reduced the number of accidents.