Answer: 
Step-by-step explanation:
According to the given information, we have
Sample size : n= 50


Since population standard deviation is unknown, so we use t-test.
Critical value for 95 percent confidence interval :

Confidence interval : 

Required 95% confidence interval : 
Answer:
Step-by-step explanation:
D
Answer:
Step-by-step explanation:
Given that transitor has a 2% defective rate, need to calculate the probability that the 10th transistor produced is the first with a defect.
The probability function is p(x=k) = (1-p)^(n-1) * p
p = (1-defective rate)^(n-1) * defective rate; n=10
p = (1-0.02)^9 * 0.02 = 0.98^9 * 0.02 = 0.01666