BSAN 202 Statistics Midterm Review

These flashcards cover key concepts and problems from the BSAN 202 Statistics midterm exam, focusing on statistical principles such as confidence intervals, distributions, expected values, and probabilities.

What is the meaning of the confidence level (1-α)?

It is a measure of the goodness of a confidence interval.

What are possible values for the Binomial distribution?

Zero (0) is a possible value for the Binomial distribution.

What is the mean of the standard normal distribution?

Zero (0).

When is the standard distribution of the sample means normal?

When the population variance is known, regardless of the sample size.

Under what condition is the standard distribution of the sample means a t-distribution?

When the sample size is small and the population standard deviation is unknown.

What is the expected value of a discrete random variable X with pmf values 0.2, 0.25, 0.6, 0.05?

1.6.

What is the expected value of Y if Y = 30X + 10 and E(X) = 1.6?

58.

What is the variance of Y if Y = 30X + 10 and V(X) is 0.54?

486.

What is the expected number of students willing to buy a new copy of a textbook if 30% of 25 students prefer a new copy?

7.5 students.

What is the probability that at least one student will buy a new copy from 25 purchasers?

Approximately 1.

For a Poisson distribution with parameter λ = 0.5, what is the probability that a disk has exactly zero missing pulses?

0.61.

What is the probability that two disks have at least one missing pulse if the Poisson distribution has λ = 1?

0.63.

For a normal distribution with mean 5% and standard deviation 20%, what is P(X > 45)?

0.023.

For the same normal distribution, what is P(X < -35%)?

0.023.

What is the two-sided 95% confidence interval for the population mean if the sample mean is 95 and σ = 10 with n = 16?

The interval is (90.1, 99.9).

What is the two-sided 98% confidence interval for the population mean with the same parameters as above?

The interval is (89.18, 100.81).