How do I solve this standard deviation problem?
2019-11-30 9:41 pm
Assume that the mathematics scores on the SAT are normally distributed with a mean of 500 and a standard deviation of 100. What percent of students who took the test have a mathematics score between 550 and 650?
回答 (3)
2019-11-30 9:51 pm
(550 - 500) / 100 = 50/100 = 0.5
(650 - 500) / 100 = 150/100 = 1.5
http://www.z-table.com/
z = 0.5 =>> 0.6915
z = 1.5 =>> 0.9332
0.9332 - 0.6915 =>
0.2417 =>
24.17%
(650 - 500) / 100 = 150/100 = 1.5
http://www.z-table.com/
z = 0.5 =>> 0.6915
z = 1.5 =>> 0.9332
0.9332 - 0.6915 =>
0.2417 =>
24.17%
2019-11-30 11:56 pm
use a z-score table to define the percentages for each of the two absolute (real) scores, and subtract to get the difference. Z score is the number of SD above (or below) mean so 550 would have a z score of +0.5, and 650 would have a zscore of +1.5. Those two z-scores correspond to a percentage of the population above the mean. subtract to get the difference between the two (the part that lies between 550 and 650).
2019-11-30 10:53 pm
Use normal distribution table to find
P (-1/2 < z < 1/2).
Answer = 38.2%
P (-1/2 < z < 1/2).
Answer = 38.2%
收錄日期: 2021-04-24 07:47:06
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https://hk.answers.yahoo.com/question/index?qid=20191130134109AAmsHvp