If a company that uses electric insulators break when in use

If a company that uses electric insulators break when in use, a short circuit can occur. Testing will tell how much force it takes to break the insulator. Force measurements are collected from a sample of 30.

Measurement from each sample is as follows: 1870, 1728, 1656, 1610, 1634, 1784, 1522, 1696, 1592, 1662, 1866, 1764, 1734, 1662, 1734, 1774,1550, 1756, 1762, 1866, 1820, 1744, 1788, 1688, 1810, 1752, 1680, 1810, 1652, 1736

a. Construct a percentage histogram and percentage polygon. (Please provide instruction on how you did it)

b. Construct a cumulative percentage polygon. (With instructions)

c. What conclusion can you reach about the strenght of the insulators, if a company requires a force measurement of at least 1,500 pounds before the insulator breaks?

Solution

The R-coding is

x=c(1870, 1728, 1656, 1610, 1634, 1784, 1522, 1696, 1592, 1662, 1866, 1764, 1734, 1662, 1734, 1774,1550, 1756, 1762, 1866, 1820, 1744, 1788, 1688, 1810, 1752, 1680, 1810, 1652, 1736)
hist(x)

x=c(1870, 1728, 1656, 1610, 1634, 1784, 1522, 1696, 1592, 1662, 1866, 1764, 1734, 1662, 1734, 1774,1550, 1756, 1762, 1866, 1820, 1744, 1788, 1688, 1810, 1752, 1680, 1810, 1652, 1736)
y=seq(1500,1900,by=13.5)
plot   (x, y, type = \"n\", xlab = \"Time\", ylab = \"Distance\")
polygon(x, y, col = \"gray\", border = \"red\")

b.

x=c(1870, 1728, 1656, 1610, 1634, 1784, 1522, 1696, 1592, 1662, 1866, 1764, 1734, 1662, 1734, 1774,1550, 1756, 1762, 1866, 1820, 1744, 1788, 1688, 1810, 1752, 1680, 1810, 1652, 1736)
y=cumsum(x)
plot   (x, y, type = \"n\", xlab = \"Time\", ylab = \"Distance\")
lines(x,y)