The answer to this question is A.
Answer:
a)
b)
c)
d)
Explanation:
From the question we are told that:
Population percentage 
Sample size 
Let x =customers ask for water
Let y =customers dose not ask for water with their meal
Generally the equation for y is mathematically given by

Generally the equation for pmf p(x) is mathematically given by

a)
Generally the probability that exactly 6 ask for water is mathematically given by


b)
Generally the probability that less than 9 ask for water with meal is mathematically given by




c)
Generally the probability that at least 3 ask for water with meal is mathematically given by

![p(x\geq3)=1-[p(0)+p(1)+p(2)]](https://tex.z-dn.net/?f=p%28x%5Cgeq3%29%3D1-%5Bp%280%29%2Bp%281%29%2Bp%282%29%5D)
![p(x\geq3)=1-[0.00001+0.0015+0.0106]](https://tex.z-dn.net/?f=p%28x%5Cgeq3%29%3D1-%5B0.00001%2B0.0015%2B0.0106%5D)
![p(x\geq3)=1-[0.0122]](https://tex.z-dn.net/?f=p%28x%5Cgeq3%29%3D1-%5B0.0122%5D)

d)
Generally the mean and standard deviation of sample size is mathematically given by
Mean

Standard deviation


Length of the pipe = 0.39 m
Third harmonic frequency = 1400 Hz
For the third harmonic:
Wavelength = 
The center of the open pipe will host a node and the nearest anti - node from the center will be at the 0.25 × wavelength
Distance from center = 0.25 × wavelength
Distance = 
Plugging the value of the length of the pipe (L) = 0.39 m = 39 cm
Distance = 
Distance from the center to the nearest anti - node = 6.5 cm
Hence, the nearest distance to the anti - node from the center = 6.5 cm
So, option C is correct.
Answer:D
Explanation: i found the answer in an answer key!