On each trial of an experiment, a participant is presented with a constant soft noise, which is interrupted at some unpredictable time by a slightly louder sound. The time it takes for the participant to react to the louder sound is recorded. The following list contains the reaction times (in milliseconds) for 9 trials of this experiment. 378, 441, 411, 378, 411, 411, 785, 513, 378 Send data to calculator (a) What is the mean of this data set? If your answer is not an integer, round your answer to one decimal place. (b) What is the median of this data set? If your answer is not an integer, round your answer to one decimal place. (c) How many modes does the data set have, and what are their values? Indicate the number of modes by clicking in the appropriate circle, and then indicate the value(s) of the mode(s), if applicable. 1 7 zero modes one mode: two modes: X 0 and Ś

Subpart b

21 subpart a

On each trial of an experiment, a subject is presented with a constant soft noise, which is interrupted at some unpredictable time by a noticeably louder sound. The time it takes for the subject to react to this louder sound is recorded. The following list contains the reaction times (in milliseconds) for the 19 trials of this experiment: 171, 212, 285, 175, 202, 269, 193, 217, 164, 231, 261, 236, 186, 257, 271, 229, 250, 296, 226 Send data to calculator Find 20th and 75th percentiles for these reaction times. (If necessary, consult a list of formulas.) (a) The 20th percentile: milliseconds (b) The 75th percentile: milliseconds

A researcher is interested in hamster wheel-running activity during the summer versus the winter. She suspects that either the hamsters will run less during the winter to conserve energy or they will run more to keep warm. She records the activity of n = 25 hamsters during June, July, and August and compares their running-wheel revolutions per hour to the activity of the same hamsters during December, January, and February. The data are collected, and the results show an average difference score of MD - 5.7 and a sum of squares of SS = 2,851.44. What is the sample standard deviation (s) for the D scores? (one decimal)

On each trial of an experiment, a subject is presented with a constant soft noise, which is interrupted at some unpredictable time by a noticeably louder sound. The time it takes for the subject to react to this louder sound is recorded. The following list contains the reaction times (in milliseconds) for the 15 trials of this experiment: 212, 236, 217, 235, 164, 257, 175, 285, 202, 193, 231,152, 269, 296, 186 Send data to calculator   Find 30th and 75th  percentiles for these reaction times.

A random selection of volunteers at a research institute have been exposed to a typical cold virus. After they started to have cold symptoms, 15 of them were given multivitamin tablets formulated to fight cold symptoms. The remaining 15 volunteers were given placebo tablets. For each individual, the length of time taken to recover from the cold is recorded. At the end of the experiment the following data are obtained. Days to recover from a cold Treated with multivitamin 4.9. 3.9, 4.9. 7.3, 3.7, 5.7, 4.3, 6.1, 4.9, 5.4, 7.7, 7.3, 4.6, 4.3, 4.6 Treated with placebo 5.1, 5.3, 5.3, 1.6, 1.6, 4.8, 4.4, 3.3, 3.7, 5.2, 5.5, 5.8, 6.5, 1.5, 5.4 Send data to calculator Send data to Excel It is known that the population standard deviation of recovery time from a cold is 1.8 days when treated with multivitamin tablets, and the population standard deviation of recovery time from a cold is 1.5 days when treated with placebo tablets. It is also known that both populations are approximately normally…

Comparing the mea Español On each trial of an experiment, a participant is presented with a constant soft noise that is interrupted by a slightly louder sound. The time it takes for the participant to react to the louder sound is recorded. The following list contains the reaction times (in milliseconds) for 25 trials of this experiment. 190, 202, 212, 221, 243, 250, 257, 271, 288, 288, 288, 309, 311, 315, 323, 335, 359, 364, 388, 418, 440, 476, 526, 603, 756 Send data to calculator Frequency ↑ 124 10- 8+ 64 4- 24 04 150 11 Send data to Excel Answer the questions below. 10 2 300 450 600 Reaction time (in milliseconds) (a) Which measures of central tendency do not exist for this data set? Choose all that apply. Check (b) Suppose that the measurement 190 (the smallest measurement in the data set) were replaced by 72. Which measures of central tendency would be affected by the change? Choose all that apply. (c) Suppose that, starting with the original data set, the largest measurement were…