Question

For full point, you need to give me your main R code and the results. Hand in your homework as a word file.

1. With R, calculate the following numbers.

=    

       

2. For the data, {2, 3, 4, 5, 6, 7, 8, 9, -3, -4}, find its maximum and minimum value.

3. Find the sum of .

4. On a recent English test, the scores were normally distributed with a mean of 74 and a standard deviation of 7. What proportion of the class would be expected to score between 60 and 80 points?

Answer 1

> data<-c(2,3,4,5,6,7,8,9,-3,-4)
> data
[1] 2 3 4 5 6 7 8 9 -3 -4

Maximum of given data--
> maximum=max(data)
> maximum
[1] 9

Minimum of given data--
> minimum=min(data)
> minimum
[1] -4

Sum of the Data--
> sum=sum(data)
> sum
[1] 37
> mean=74
> sd=7

p(60 < z < 80) is

> z60<-pnorm(60,74,7)
> z60
[1] 0.02275013
> z80<-pnorm(80,74,7)
> z80
[1] 0.804317
> z=z80-z60
> z
[1] 0.7815669
p(60 < z < 80) = 0.7815669

So, about 78% of the class is expected to score between 60 and 80 on the test.