Math
posted by Michael .
The diameters of grapefruits in a certain orchard are normally distributed with a mean of 5.52 inches and a standard deviation of 0.46 inches
(A) What percentage of the grapefruits in this orchard is larger than 5.45 inches?
(B) A random sample of 100 grapefruits is gathered and the mean diameter is calculated. What is the probability that the sample mean is greater than 5.45 inches

Math 
MathMate
Normalize!
Calculate Z=(Xμ)/σ
where
Z = Z score found in standard normal distribution tables
X = value of random variable, the diameter of 5.45 inchs
μ = mean diameter of population, 5.52 inches
σ = standard deviation of population, 0.46 inch.
Look up a standard normal distribution, which is usually given in percentage of population less than the Zscore, i.e. left tail (but check if this is the case).
What you need is the right tail, i.e. percentage of population greater than the Zscore. To get this from the table, subtract the left tail from ONE to get the righttail.
Respond to this Question
Similar Questions

measurements
Which is the following is the best deal? A: six small grapefruits for a $1 B: four medium grapefruits for a $1 C: Three large grapefruits for a $1 Assume that all the grapefruits are spherical, that the small grapefruits have a diameter 
Statistics
Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 
Statistics
Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 
math
The diameters of a wooden dowel produced by a new machine are normally distributed with a mean of 0.55 inches and a standard deviation of 0.01 inches. What percent of the dowels will have a diameter less than 0.57? 
statistics
The diameters of apples in a certain orchard are normally distributed with a mean of 4.77 inches and a standard deviation of 0.43 inches. Show all work. (A) What percentage of the apples in this orchard is larger than 4.71 inches? 
statistics
The diameters of grapefruits in a certain orchard are normally distributed with a mean of 6.45 inches and a standard deviation of 0.45 inches. Show all work. (A) What percentage of the grapefruits in this orchard have diameters less … 
statistics
The diameters of apples in a certain orchard are normally distributed with a mean of 4.77 inches and a standard deviation of 0.43 inches. Show all work. (A) What percentage of the apples in this orchard is larger than 4.71 inches? 
math
The diameters of pencils produced by a certain machine are normally distributed with a mean of 0.30 inches and a standard deviation of 0.01 inches. In a random sample of 460 pencils, approximately how many would you expect to have … 
Elementary Statistics
The diameters of pencils produced by a certain machine are normally distributed with a mean of 0.39 inches and a standard deviation of 0.04 inches. If 500 pencils are selected how many would you expect to have a diameter more than … 
Math
The diameters of bolts produced by a certain machine are normally distributed with a mean of 0.25 inches and a standard deviation of 0.01 inches. What percentage of bolts will have a diameter greater than 0.24 inches?