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dediganss

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- It is intended to collect samples from a Normal population with a standard deviation of 9. For a confidence level of 80%, determine the amplitude of the confidence interval for the population average in the case of a sample of size 81. Pick one:a. 1,28

c. 1,44

d. 2,30

2) A sample of 16 observations independent of a Normal (2, 4) is collected. If Xb is the sample mean, determine the probability P [Xb> 1]. Pick one:a. 95,45%

b. 50,00%

c. 97,73%

d. 84,13%

3) A random variable has a uniform distribution in the set {-2, 2, 3}. For a random sample of size 2, the sample mean is Xb = (X1 + X2) / 2. Determine hope E [Xb]. Pick one:

a. 4/3

b. -2/3

c. -1/3

d. 1

4) A sample of 36 observations from a Normal (mu, 9) was collected and provided a sample mean of 8. Build a 95% Confidence Interval for the population mean. Pick one:

a. (7,28 ; 8,72)

b. (7,1775 ; 8,8225

c. (7,02 ; 8,98)

d. (7,36 ; 8,64)

5) A Bernoulli random variable has a probability of success p = 0.50. Considering random samples of size 3, the sample mean is given by Xb = (X1 + X2 + X3) / 3. Determine the probability P [Xb! = 2/3]. Pick one:

a. 7/8

b. 5/8

c. 3/8

d. 3/4