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.
Step 3. Cook the roast at 300 degrees F for 15 to 30 minutes per pound, depending on whether you want rare, medium or well-done beef. Cook for 3 to 4 hours total for a well-done roast; the meat should fall apart when done. Use an instant-read thermometer to check for doneness.