Answer:
54
Step-by-step explanation:
34 + 4 ⋅ 5 (by PEDMAS, do multiply first)
= 34 + 20
= 54
Standard deviation is calculated by
1. calculate mean, m
2. calculate deviation of EACH entry of data set from the mean, i.e.
d=(x-m)
3. calculate mean of square of deviations (d^2)/n to get variance,v
4. take square-root of variance to get standard deviation.
For example,
To find the standard deviation of data set {3,7,8}
1. mean=(3+7+8)/3=6
2. deviations, di={3-6,7-6,8-6}={-3,1,2}
3. squares of deviations, di^2={9,1,4}
4. mean of squares of deviations=(9+1+4)/3=14/3
Standard deviation=sqrt(14/3)=2.16
For the given data set, if you follow the above steps, you would get
sum=400
mean=400/9
variance (mean square of deviations)=8246/81
standard deviation=sqrt(8246/81)=sqrt(8246)/9
Answer:
5.73 hours
Step-by-step explanation:
70% decay means 30% remains
.3 = (1/2)^(t/3.3)
take the log of both sides
log.3 = t/3.3 * log1/2
Divide both sides by log 1/2
log.3 / log1/2 = t/3.3
use calculator
1.736965594166206 = t/3.3
multiply both sides by 3.3
5.73198646074848 = t
rounded
t = 5.73 hours
