Mean is calculated by adding all the values from a data set together (I.e. 55+57+59+62+63+140) and than dividing that number by how many values were added; in this case that would be (436/6) which gives us 72.66666.......
If we take the knowledge learned from the explanation above and do the same thing but exclude the value of 140. ((55+57+59+62+63)/5)
which gives us 59.2 as our mean, which is decreased from 72.6666 that it was before.
I however do not know question 3 as I do not fully know IQR, sorry.
Make sure you convert these numbers into one unit. Convert everything to yard. Just convert the feet and inches in yard since it's the biggest unit, and then add them together. You should get a fraction not a whole number.
