Staals half
1 gram left
0.3 grams left
half lives are normally written in years
it goes likt this

A=final amount
P=initila amount
t=time elapsed 
h=time half life is (same units as time)
let's use days as the units of time
we are given
initial amount=1gram
final amount=0.3gram
time=4 days
so

solve for h

take the ln of both sides


times both sides by h

divide both sides by ln(0.3)

use calculator
h=2.30287
3 sig figs
h=2.303 days
 
        
        
        
Answer:
It would be C
Step-by-step explanation:
 
        
             
        
        
        
Answer:
(4,3)
Step-by-step explanation:
 
        
             
        
        
        
Answer:
No, a convenience sample was taken.Therefore, the sample may not be representative of all college students in terms of number of hours studied per week.
Step-by-step explanation:
One of the important conditions required in other to estimate the mean of the population from the confidence interval. Requires that the data must be a random Sample. This is to ensure that sample values are not biased and as such are representative of the larger group of data.
However, in the scenario described above, the sample chose. Are friend's of the student, this makes the data lack randomness as those who aren't friends to the student do not stand a chance of being selected. The sampling procedure employed is called convenience sampling. 
 
        
             
        
        
        
The first question is D because if the
 y-intercept is 1 then every point moves down three units. 
The second question is J because a vertical line is not a function so it can’t be a linear function.