Answer:
n = 61 costumers
Step-by-step explanation:
For calculating the number of costumers he should sample we use the next equation:

                           Where E is the error that we are prepared to accept, in this  case E = 0.15
 
How we don't know the value of p, we can estimate it like p = 0.5
∝ = 1-0.98 = 0.02
1-∝/2 = 0.99


n = 60.32 costumers
n ≈ 61 costumers
 
        
             
        
        
        
Answer:
71424
Step-by-step explanation:
 
        
                    
             
        
        
        
The answer is 1/140 
Work Shown 
0.3 / 42
Convert and Rewrite 
3/10 x 1/42 
Reduce The Numbers With the greatest Common divisor 3 
1/10 x 1/14 
Multiply the fractions 
1/140 or 
AlTernative Form  0.007114285 , -1 over 140
I Hope This Help 
-Dante
 
        
             
        
        
        
Answer:
6.46 
Step-by-step explanation:
h(t) = (1/2) + v0t + h0
 + v0t + h0
 
Origin is at surface of water (h = 0), up is positive.
 
a = -g = -9.8 m/
v0 = 25 m/s
h0 = 50 m
 
h(t) = -4.9t2 + 25t + 50
 
Find t when
 
7 =  + 25t + 50
 + 25t + 50
 
 - 25t - 43 = 0
 - 25t - 43 = 0
 
t = [1/(2*4.9)] [25 ±√( + 4*4.9*43)]
 + 4*4.9*43)]
 
t = (0.102)(25 ± 38.312)
 
t > 0 ⇒ use only the positive square root
 
t = (0.102)(25 + 38.312) ≅ 6.46 s
 
It is 7m above the water at about 6.46 s