The average height of flowering cherry trees in a nursery is 11 feet. If the heights are normally distributed with a stand deviation of 1.6 feet, find the probabilty that a tree is less than 13 feet.

This sounds like a homework question. We won't do your homework for you. You've got to put some effort in if you want help.

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Originally Posted by justcurious55

this sounds like a homework question. we won't do your homework for you. you've got to put some effort in if you want help.

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Not asking for it to be done for me but I'm totally new to statistics and I struggle with word problems. Just looking for some dorections but thanks anyway.

Standardize your values to the z value.



Then, look up for the probability of that z score in your z table. Be careful of what probability you are looking for! Better get a quick sketch of the bell shaped curve, and shade the area you are looking for.

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Better get a quick sketch of the bell shaped curve, and shade the area you are looking for.

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That's about the best advice you could get. Draw your curve and draw a z line underneath. Your standard deviation is 1.6 so that's the distance to the first notch, etc. You can easily see that 13 is a bit over 1 deviation. A z-score is how many standard deviations. i.e. how many 1.6's away from the mean is 13? So you're looking for the same point on the z line, cause that's "standardized" which is what your z equation will give you.

You want less than, so you're going left of the red line. So look that up on your z chart.