Please help me with this problem I been stuck in this problem for 45 min and don't know how to go about it ????

2. A longitudinal study of human growth was started in 1929 at the Berkeley Institute of Human Development. The scatter diagram below shows the heights of 64 boys, measured at ages 4 and 18. Answer the following. 78 76 74 Height at sighteen B6 62 36 38 40 42 44 46 48 Height at four Figure 1: Boys Scatter. (a) Estimate the SD of height at age 4. (b) Estimate the average of height at age 18. (c) Estimate the correlation coefficient. (d) Which is the SD line, solid or dashed