A standard penetration test was carried out in a normally consolidated sand at 7.62 m depth where the N60 was determined to be 28. The unit weight of the sand is 17.29 kN/m3 , and the grain-size distribution suggests that D50 5 1.2 mm and Cu 5 3.2. The age of the soil since deposition is approximately 5000 years. Determine the relative density using the different correlations discussed in Section 3.15 [i. e., Eqs. (3.21), (3.22), (3.23), (3.24), and (3.28)].