Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °
You are not logged in.
Post a reply
Topic review (newest first)
where mu is the mean (340) sigma is the sd (45) and phi is the function that converts this into a probability.
Use this page:
http://www.mathsisfun.com/data/standard … table.html
This interactive graph shows the probabilities as percentages in three possible ways. Click the 'up to z' button to get the 7% area you want. There is a more accurate table of values below the graph.
Once you have z, you can solve for x
What is the z-score for "7%"?
birth weight in US are normally distributed with mean of 340g and a strandard deviation of 45g. If a hospital plans to set up observation condition for the lightest 7% of the babies, what weight is used for the cutoff separating the lightest 7% from the others?