Question 1: Let's say that in an area there is a male-to-female ratio of 12:13. An epidemic is spreading in this area with a 0.6% chance of infection in males and 0.35% in females. 1. Calculate the incidence of people in this area? 2. If you meet a person in the area who doesn't have the disease, the possibility that this person has sex | Which province is higher?

Question 2: The number of customers visiting a restaurant in the chain of restaurants of KFC Vietnam in one hour is a random variable X with a Poisson distribution. Know that there are 5 customers on average every 10 minutes.
1. Find the probability that 40 customers come to the restaurant in one hour.
2. Calculate the expectation and standard deviation of X.

Question 3: The diameter of a device manufactured by company B is a random variable X with a normal distribution with c = 0.01, Take one sample Randomly n=10 devices found an average diameter of 1.5045cm.
a. With a 95% confidence interval, find a symmetric confidence interval for the mean diameter (1) of the device.
b. At least how many of these devices must be taken to estimate the symmetric confidence interval for A with an error of not more than 0.003 given the 95% confidence interval.
c. Company B claims that the average diameter of each device is 1.5 cm. Test the above statement with significance level a=0.01.