only looking for help with 123 thank you Standard 35 Integra

only looking for help with 1,2,3
thank you

Standard 3-5 Integrated Math 3 Per Name: Sample Group Test Scores 75, 80,95, 85,80 1. Find the mean, median, mode and range. median: mode: 2. What is the probability of score being over 80? 3. What are the odds of a score being less than 85? 4. Find the standard deviation, round it to the nearest whole number. 5. set up the normal distribution curve. 6. If 15,000 people will take the test, how many sbould score between 83 and 97? 7. 40,000 people will take the test, how many should score less than 76?

Solution

mean :
(75 + 80 + 95 + 85 + 80)/5
mean = 83

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median :
Arrange in ascending order first...

75 80 80 85 95

So, median 3rd term = 80

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mode :
80 occurs most number of times(twice)

So mode = 80

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range :
Largest - least
95 - 75

range = 20

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2)
Score over 80 :
We have 85 and 95

So, 2/5 or 40% or 0.4

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3)
Less than 85 :
P(less than 85) = 3/5

So, odds less than 85 is : P / (1 - P)

= (3/5) / (1 - 3/5)

= (3/5) / (2/5)

3/2

or 3 : 2 odds