Question

Of great importance to residents of central Florida is the amount of radioactive material present in the soul of reclaimed phosphate mining areas. Measurements of the amount of 238U in 25 soul samples were as follows (measurements in picocuris per gram): 0.74, 0.32, 1.66, 3.59, 4.55, 6.47, 9.99, 0.7, 0.37, 0.76, 1.9, 1.77, 2.42, 1.09, 2.03, 2.69,2.41, 0.54, 8.32, 5.70, 0.75, 1.96, 3.36, 4.06, and 12.48. Construct a relative frequency histogram for these data.

Answer 1

Answer:

See figure attached and explanation below.

Step-by-step explanation:

For this case we have the following dataset given:

0.74, 0.32, 1.66, 3.59, 4.55, 6.47, 9.99, 0.7, 0.37, 0.76, 1.9, 1.77, 2.42, 1.09, 2.03, 2.69,2.41, 0.54, 8.32, 5.70, 0.75, 1.96, 3.36, 4.06, 12.48

And for this case we can use the followinf R code to create the frequency histogram.

> x<-c(0.74, 0.32, 1.66, 3.59, 4.55, 6.47, 9.99,0.7, 0.37, 0.76, 1.9, 1.77, 2.42, 1.09, 2.03, 2.69,2.41, 0.54, 8.32, 5.70, 0.75, 1.96, 3.36, 4.06,12.48)

> length(x)

[1] 25

> hist(x, prob=TRUE)

And for this case we have the histogram on the figure attached. For the number of classes we use the formula of sturges:

$k = 1 +3.322 log (n)= 1+3.3 log(25)= 5.61$

And for this case we have approximately 6 classes. And that's what we can see on the figure attached

As we can see most of the values are on the left so then we have a right skewed to the right and the distribution is assymetrical, with most of the values between 0 and 6