Se quiere levantar 500 Kg de peso probando tres dispositivos. El primero está formado por dos poleas móviles. El segundo es un aparejo vertical de 4 poleas, dos fijas y dos móviles; el último
posee una polea fija y tres móviles.
Dibújalos y calcula la fuerza que habrá que aplicar en cada caso.

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 360, a standard deviation of 4, and a margin of error of 2.5%

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?

Arational number that is equivalent to -20/4?