Can somebody check my answers?

three dentists wanted to compare the ages of their patients. they each calculated their patients’ mean age and the mean absolute deviation of their ages. they displayed the results in a table.

which statements are true? choose exactly two answers that are correct.

image:
dentist mean patient age mad
appiah 43 9.7
cantwell 29 13.9
singh 41 14.1

a. dr. appiah’s patients’ ages vary more than do dr. cantwell’s patients’ ages.

b. dr. appiah’s patients’ ages vary less than do dr. singh’s patients’ ages.

c. dr. cantwell’s patients’ ages and dr. singh’s patients’ ages vary about the same amount.

d. dr. singh’s patients’ ages and dr. appiah’s patients’ ages vary about the same amount.

i think it's a and b.

10 points for the correct answer!

Option B is right.

Step-by-step explanation:

Given that Three dentists wanted to compare the ages of their patients. They each calculated their patients’ mean age and the mean absolute deviation of their ages. They displayed the results in a table.  

Dentist      Mean      MAD

Appiah         43         9.7

Cantwell       29       13.9

Singh            41         14.1

Mean absolute deviaiton is a measure of deviations of all entries from the mean.

We find that maximum variation is that of Singh followed by Cantwell and Appaiah.

Option A is wrong as Dr. Appiah’s patients’ ages do not vary more than do Dr. Cantwell’s patients’ ages.  

B. is true.

Dr. Appiah’s patients’ ages vary less than do Dr. Singh’s patients’ ages.  

C is false  Dr. Cantwell’s patients’ ages and Dr. Singh’s patients’ ages vary about the same since tey are 13.9 and 14.1 hence different.

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

the correct answer is $7.38

step-by-step explanation: