341 point What is the purpose of a control group in an experiment? to ensure that the effect being measured is due to the independent variable alone. for comparison to the results of other experiments. to control the dependent variable. to prove the prediction. to prove the hypothesis.

(a) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The function is increasing over the open interval(s) (Type your answer in interval notation. Use a comma to separate answers as needed.) B. The function is never increasing.

Suppose that the average number of Facebook friends users have is normally distributed with a mean of 147 and a standard deviation of about 55 . Assume forty-three individuals are randomly chosen. Answer the following questions. Round all answers to 4 decimal places where possible. a. What is the distribution of \( \bar{x} \) ? \( \bar{x}-\mathrm{N} \). b. For the group of 43 , find the probability that the average number of friends is more than 150 . c. Find the third quartile for the average number of Facebook friends. d. For part b), is the assumption that the distribution is normal necessary? No Yes

Solve by Substitution \( \begin{array}{l}4 x-3 y=23 \\ 3 x+y=14\end{array} \) One solution: No solution Enter a point [more..I Infinite number of solutions

A student is performing an experiment to measure the acceleration due to gravity and obtains a value of 10.0 m/s2. The accepted value for the acceleration due to gravity is 9.8 m/s2. What is the percentage error in the student's measurement?

ii. \( \int_{-3}^{0} \sqrt{1-x} d u \)