Today we mainly focused on binomial distributions and how to determine the values of Z on the table. For example, we worked on homework 9 and Mr. Marchetti explained how to find the "gaps in the table." Basically, if we want to find the number between Z=1.3 and Z=1.4, there is 1/3 of difference between them. Then we determine the value by getting the difference between the values of Z=1.3 and Z=1.4. Then we divided the difference by .33.
After discussing homework 9, we talked about "A Normal Poll," Alex explained how to find the probability that Harriet's poll will show Henry as the winner by using a standard distribution table. Since the true proportion was .6 and the standard deviation .069, we used ratios to get the probability. Alex moved the decimal point of sigma two places to the right, so he used the following equation: 1/6.9=x/10, after cross multiplying, x=1.45. He used the table as a reference to get the value of 1.45 SD from the mean. The value was 82.5, then he divided 82.5 by 2 and added the result to 50, this was equal to 92%.
Then Mr. Marchetti returned the graded POWs and announced that POW 10 will be due next Friday. There is no homework for tomorrow, but there's a quiz on standard distributions and binomial probabilities tomorrow.
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