A student wanted to know the most effective way to grow bacteria in a lab. He conducted a descriptive investigation instead of an experimental investigation. What is a limitation of his investigation? O A descriptive investigation cannot show a cause-and-effect relationship between bacteria growth and possible factors affecting growth. O A descriptive investigation is always more expensive than an experimental investigation. aner O A descriptive investigation usually does not involve much data collection to support a hypothesis. O A descriptive investigation provides little prior knowledge or background information about bacteria growth.

Which of the following are considered needs? check all that apply

Quick calculate the roi dollar amount and percentage for these example investments. a. you invest $50 in a government bond that says you can redeem it a year later for $55. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage. b. you invest $200 in stocks and sell them one year later for $230. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage.

Penny poodle wanted to know which dog obedience training program was more effective: puppy pride, the approach she has been using for any years, or doggie do-right, a new approach. penny convinced 50 human companions of untrained dogs to participate in her study. the dogs and their humans were randomly assigned to complete the puppy pride or doggie do-right course. at the end of the training programs, all of the dogs were scored on their level of obedience on a standardized dog obedience checklist (scores could range from 10 to 100). the design of this study is: