Answer:
Mean = 339 hours
Standard deviation = 54 hours
Step-by-step explanation:
We are given that approximately 2.5% of the bulbs have lives exceeding 445 hours
So,P(x>445) = 0.025
P(x<445) =1- 0.025 =0.975
z value for 0.975 is 1.96
Formula : 
So, 
--A
Now we are given that approximately 16% have lives exceeding 393 hours,
So,P(x>393) = 0.16
P(x<393) =1- 0.16 =0.84
z value for 0.84 is 1
Formula : 
So, 
---B
Solve A and B
Substitute the value of
from B in A






Substitute the value in B

So, mean = 339 hours
Standard deviation = 54 hours
Answer:
2 × 10⁵
Step-by-step explanation:
The following data were obtained from the question:
6×10⁹/ 3×10⁴ =?
The above expression can be simplified as follow:
6×10⁹/ 3×10⁴ = 6×10⁹ ÷ 3×10⁴
Recall:
Aᵐ ÷ Aⁿ = Aᵐ ¯ ⁿ
Therefore,
6×10⁹ ÷ 3×10⁴ = (6/3) × 10⁹ ¯ ⁴
6×10⁹ ÷ 3×10⁴ = 2 × 10⁵
Thus, 6×10⁹/ 3×10⁴ is equal to 2 × 10⁵
Assuming that the ball is launch from the ground. the initial velocity would be equal to its final velocity when it reach the ground. this is because the acceleration due to gravity is working on the ball, when it goes up decelerates up to zero, then falls back then acceleartes again until it reach the groun, where the velocity is 150 m/s
Answer:
x > 4
Step-by-step explanation:
X-3>1
Add 3 to each side
X-3+3>1+3
x > 4