
The power of placebo. A study of pain relief following arthroscopic knee surgery used two control groups to compare to a surgery group. One of the control groups had their knees opened and “lavaged,” where the inside of the knee is flushed out, but no scraping or other surgical manipulation is performed. The other control group had their knees opened and then closed again, with no treatment at all. The graphs below display the average pain levels reported for the three groups. Which, if any, treatment appears to be effective?

Want to see the full answer?
Check out a sample textbook solution
Chapter 9 Solutions
The Heart of Mathematics: An Invitation to Effective Thinking
Additional Math Textbook Solutions
A Problem Solving Approach To Mathematics For Elementary School Teachers (13th Edition)
Calculus: Early Transcendentals (2nd Edition)
Elementary Statistics
Elementary Statistics (13th Edition)
Calculus for Business, Economics, Life Sciences, and Social Sciences (14th Edition)
A First Course in Probability (10th Edition)
- B1 The x distribution is a special case of Gamma distribution (not to be confused with gamma function; see below). The density function of the Gamma distribution with parameters and k is given by where -1 e -x/0 (x) = = г(k) Øk if x > 0, and otherwise, г(k) = √ ₁ k-1-x dx x' e is the gamma function. (a) For every k ≥ 1, 0 > 0, find the mode of the density. Hint: The algebra can be simplified by appropriate use of logarithms. ~ Now suppose that X1,..., Xn id Exp(\) and that we have a prior belief in A which is consistent with a prior distribution X. Gamma(a, b), for some a, ß, i.e. the prior density of is Baxa-1-BA T(a) e = so 01/ẞ and k = a. (b) Write down the likelihood, and show that the posterior distribution for \ is also a Gamma distribution, but with parameters a +n and B + Σ Xi. (c) Find the mode of the posterior distribution and examine the behaviour as n → ∞.arrow_forwardFind the differential of the function f(x, y) = 2x² - 2xy – 5y² at the point (-6, -5) using Ax = 0.3 and Ay = 0.05. dz = Now find Az and compare it to your answer above Ax= Hint: If entering a decimal, round to at least 5 placesarrow_forwardFind the differential of the function f(x, y) = −8x√y at the point (1,3) using Ax = 0.25 and Ay = -0.15. dz Now find Az and compare it to your answer above Az = Hint: If entering a decimal, round to at least 5 placesarrow_forward
- please dont use chat gpt i need to underarrow_forwardChris Lynch plans to invest $200 into a money market account. Find the interest rate that is needed for the money to grow to $1,800 in 12 years if the interest is compounded quarterly. The rate is %. (Round to the nearest percent.)arrow_forwardFind the interest earned on $10,000 invested for 6 years at 6% interest compounded as follows. a. Annually b. Semiannually (twice a year) c. Quarterly d. Monthly e. Continuouslyarrow_forward
- 6.9x y= 100-x a. Find the cost of removing each percent of pollutants: 50%; 70%; 80%; 90%; 95%; 98%; 99%. 50% y = 70% y = 80% y = 90% YF 95% y = 98% y= 99% V =arrow_forwardThe cost per ton, y, to build an oil tanker of x thousand deadweight tons was approximated by 215,000 C(x)= x+485 C(25) C(100) C(300) =1 C(50) = = C(200) = C(400) =arrow_forwardA company manages an electronic equipment store and has ordered 200200 LCD TVs for a special sale. The list price for each TV is $200200 with a trade discount series of 6 divided by 10 divided by 2.6/10/2. Find the net price of the order by using the net decimal equivalent.arrow_forward
- According to flightstats.com, American Airlines flights from Dallas to Chicago are on time 80% of the time. Suppose 10 flights are randomly selected, and the number of on-time flights is recorded. (a) Explain why this is a binomial experiment. (b) Determine the values of n and p. (c) Find and interpret the probability that exactly 6 flights are on time. (d) Find and interpret the probability that fewer than 6 flights are on time. (e) Find and interpret the probability that at least 6 flights are on time. (f) Find and interpret the probability that between 4 and 6 flights, inclusive, are on time.arrow_forwardi need help pleasearrow_forwardShow how you get critical values of 1.65, -1.65, and $1.96 for a right-tailed, left- tailed, and two-tailed hypothesis test (use a = 0.05 and assume a large sample size).arrow_forward
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillFunctions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage Learning
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage LearningHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL




