18X.7. Approximation to Normal Distribution

Try these first

1. 1.

   What is the continuity correction factor when estimating a binomial distribution using a normal distribution?

   Hint

   Think about how we adjust for the differences between discrete and continuous.

2. 2.

   State the Z-score formula.

   Hint

   What does the Z-score help us do?

3. 3.

   What is the Z-score formula for approximating a binomial distribution?

   Hint

   Think about standard deviations.

4. 4.

   True or False: The normal approximation for the binomial distribution is only valid when p is close to 0 or 1.

   • True
   • False

   Hint

   Recall when we said the approximation is effective.

5. 5.

   A researcher finds that in a population of 1000 people, 40% are left-handed. If we sample 100 individuals, use the normal approximation to find the probability that at least 45 are left-handed.

   Hint

   Start with np and npq calculations.

6. 6.

   You conduct an experiment with 50 trials where the probability of success is 0.3. Use the normal approximation to find the probability of getting between 10 and 20 successes.

   Hint

   Don't forget to adjust your limits!