Question

A statistics professor plans classes so carefully that the lengths of her classes are uniformly distributed between 48.048.0 and 53.053.0 minutes. Find the probability that a given class period runs between 50.550.5 and 51.7551.75 minutes.

Answer 1

Answer:

The probability of selecting a class that runs between 50.550.5 and 51.7551.75 minutes is 0.24

Step-by-step explanation:

A uniform distribution is a flat distribution that has the same probability density for every number. The area under the graph of the distribution must be 1. Since this distribution runs from 48.048.0 to 53.053.0  minutes,

it has a range of 5.005 (53.053.0 - 48.048.0).

The density must be 1/5.005 ≅ 0.2, so that 5.005*0.2 ≅ 1.0.

 

To find the probability of being between two numbers multiply the range between the numbers by the probability density.

range:51.7551.75 - 50.550.5 ≅ 1.2

1.2*0.2 = 0.24

P(50.550.5 < x < 51.7551.75) = 0.24

The probability of selecting a class that runs between 50.550.5 and 51.7551.75 minutes is 0.24

Answer 2

Answer:

Probability = 0.241

Step-by-step explanation:

We can find the probability that a given class period runs through the given time recognizing that a uniform probability distribution is mostly a rectangle with an area equal to 1.

Therefore,

Probability = 51.7551 - 50.550/53.053 - 48.0480 = 1.2057/5.005

= 0.241