Each group contained 25 cattails. All of the groups were grown in the same type of soil, they all received the same amount of light, and they were all kept at the same
Cooking at a constant oven temperature of 300Â°F (160Â°C), a 5- to 8-lb standing rib roast will take 17-19 minutes per pound for rare, 20-22 for medium rare, 23-25 minutes for medium, and 27-30 minutes for well done.ow long and at what temperature should I cook a beef roast in the oven? Roasting is a great cooking method for a large, tender cut of beef  such as a rib or sirloin roast.
(Cooking times will vary â the following times are determined from a 3.5 pound roast!). 1  For medium-rare meat the roast should take about 50-55 minutes. 2  A medium roast will take approximately 1 hour exactly. 3  A well done roast will take about 1 hour and 10-15 minutes. It should reach 150 degrees F for a medium-rare roast, 160 degrees F for a medium roast, and 175 degrees F for a rare roast. 2  Cooking temperatures vary depending on the weight of your roast.