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:
6.46
Step-by-step explanation:
h(t) = (1/2) + 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 - 43 = 0
t = [1/(2*4.9)] [25 ±√( + 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