Question

the table shows the scores of 20 people who took a paramedic licensing test. Find the mean and standard deviation of the data. find the standard deviation for the follow set: (the mean for the data has been found and equals 76). [round the standard deviation to three decimal places as needed]

Answer 1

mean=(71*5+72*1+75*5+79*6+80*2+84*1)/(5+1+5+6+2+1)

mean=1,520/20

mean=76

Part 2

Find out the deviation standard

For each value of the score, subtract the mean, square the result and multiply by the frequency

so

(71-76)^2=25*5=125

(72-76)^2=16*1=16

(75-76)^2=1*5=5

(79-76)^2=9*6=54

(80-76)^2=16*2=32

(84-76)^2=64*1=64

Adds the numbers

(125+16+5+54+32+64)=296

Divide by (n-1)

n=20

so

296/(20-1)=296/19

the deviation standard is the square root of 296/19

therefore

deviation standard=3.947