A random sample of 15 subjects was asked to perform a given task. The time in seconds it took each of them to complete the task is recorded below.37, 33, 28, 29, 37, 50, 28, 45, 49, 30, 39, 27, 40, 48, 26Send data to calculatorIf we assume that the completion times are normally distributed, find a 95% confidence interval for the true mean completion time for this task. Give the lower limit and upper limit of the 95% confidence interval.Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.)Lower limit: Upper limit:

How many observations should a stopwatch time-study analyst plan for in a task that has a standard deviation of 1.26 minutes per piece if the goal is to estimate the mean time per piece to within 0.1 minute with a confidence of 99.0 percent? (Round the intermediate calculations to 2 decimal places. Round the final answer to the next whole number.)

An analyst has timed a metal-cutting task for 50 cycles. The average time per cycle was 11.9 minutes, and the standard deviation was 1.32 minutes for a worker with a performance rating of 130 percent. Assume an allowance of 17 percent of task time. Calculate the standard time for this task. (Do not round intermediate calculations. Round the final answer to 2 decimal places.)

Juana is interested in estimating how long it takes students at her school to complete a maze she designed. She takes a random sample of   students and records how long it takes each of them to complete the maze. They work separately from each other, so Juana is willing to assume independence. Here are the data with summary statistics:Player     Time (minutes)     Mean   seconds Standard deviation   seconds Assume that all conditions for inference are met for this sample.Which of the following is a   confidence interval for the mean time (in seconds) it takes students to complete this maze?Choose 1 answer:Choose 1 answer:(Choice A)    A  (Choice B)    B  (Choice C)    C  (Choice D)    D (Choice E)    E

A simple random sample of seven (7) students is selected, and the students are asked how much time they spent studying for their University subjects (combined) outside class times. From past experience, it is known that these times (in hours) are distributed normally.The times (in hours) for the sample of students are as follows:2.3 7.2 4.5 12.5 6.6 2.5 5.5Based on these results, a confidence interval estimate for the population mean is found to be 5.9 ± 2.6.The level of confidence the researcher has used is closest to:-Group of answer choices95%90%97.5%99%

An intelligence test that has a maximum time for completion of 45 minutes was recently administered to a group of 21 people. Their respective times for completion (in minutes) were as follows.22, 26, 32, 33, 33, 34, 36, 37, 37, 37, 38, 39, 39, 41, 42, 42, 42, 43, 43, 43, 43Send data to calculator86420Frequency11478202530354045Time for completion (in minutes)(a) For these data, which measures of central tendency take more than one value? Choose all that apply.MeanMedianModeNone of these measures(b) Suppose that the measurement 22 (the smallest measurement in the data set) were replaced by 10. Which measures of central tendency would be affected by the change? Choose all that apply.MeanMedianModeNone of these measures(c) Suppose that, starting with the original data set, the smallest measurement were removed. Which measures of central tendency would be changed from those of the original data set? Choose all that apply.MeanMedianModeNone of these measures(d) Which of the following best describes the distribution of the original data? Choose only one.