Median: Order the values from lowest to highest: 45, 49, 50, 56, 56, 58, 67. Pick the middle value. Answer = 56 g.Mode: The most common value. Answer = 56 g.Mean: Add all the values up, then divide the result by the number of values: 45 + 49 + 50 + 56 + 56 + 58 + 67 = 381, then 381 / 7 = 54.4 g. You could round this to 54 g, because the other numbers are given to 0 decimal places (or also to 2 significant figures.). Answer = 54 g.
Bonus:Calculate the mean in reverse. So 61 X 7 = 427, then 427 - 45 - 49 - 50 - 56 - 56 - 58 - 67 = 46 g. Answer = 46 g.