The proportion of left-handed people in the general population is about 0.1. Suppose a random sample of 225 people is observed. Using our "rule of thumb," can we use normal approximation values for this sampling distribution? Yes + np and nq = (Click to view hint) What is the mean of the sample proportion? Hp (Click to view hint) What is the standard error? E (Click to view hint) What interval is almost certain (probability 0.997) to contain the sample proportion of left-handed people? The sample proportion is almost certain to be between and (Click to view hint) In a sample of 225 people, would it be unusual to find that 40 people in the sample are left-handed? Yes (Click to view hint) Find the approximate probability of at least 30 in 225 of being left-handed. What is the sample proportion? P (Round to the nearest hundredth.) (Click to view hint) Write the problem using probability notation. P(p 2 * 0.13) What is the z-score? P(p > 0.13) = P(z z ) (Click to view hint) Which illustration (below) shows the area represented by this probability? Curve 5