The heights of a certain species of plant are normally distributed, with mean 23 cm and standard deviation 1 cm. What is the probability that a plant chosen at random will be will be between 20.5 and 25.5 cm tall?

Question

The heights of a certain species of plant are normally distributed, with mean 23 cm and standard deviation  1 cm. What is the probability that a plant chosen at random will be will be between  20.5 and 25.5  cm tall?

anonymous · Answer

do you know about converting to standard normal and using z score?

anonymous · Answer

im learning it sorta

anonymous · Answer

ok well the formula to convert to a value of z:

$$(X-\mu)/\sigma$$

anonymous · Answer

so you would have (25.5-23)/1 and (20.5-23)/1

-2.5<z<2.5

anonymous · Answer

then you can look up the probability on a standard normal chart.  Try that and let me know if you need help