a) here as k score=(X-mean)/std deviation
therefore P(55<X<75)=P((55-65)/5<Z<(75-65)/5)=P(-2<Z<2) =95%
b)
P(60<X<70)=P((60-65)/5<Z<(70-65)/5)=P(-1<Z<1) =68.0%
(2 points) Suppose we have a normally-distributed population that has a mean of 65 and a...
Scores on a test are normally distributed with a mean of 70 and standard deviation of 10. Applying the Empirical Rule, we would expect the middle 95% of scores to fall between what two values? 40 and 100 50 and 90 55 and 85 60 and 80 65 and 75
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Scores on an exam are normally distributed with a mean of 65 and a standard deviation of 9. Find the percent of the scores that satisfies the following: (a) Less than 54 (b) At least 80 (c) Between 70 and 86