For this class, the first quiz had a mean of 90.4% with a standard deviation od 16.6%. The homework scores have a mean of 81.7% with a standard deviation of 22.28%. Suppose you scored 90% on quiz one and have a homework total of 84%.

A)are the reported means and standard deviations, parameters or statistics? explain

b)a student is chosen at random. His homework scores are higher than 65% of the class. find his homework score.

A) sorry, never took the subject so do not know the words, am physics major.

B)
homework mean = 81.7
homework s = 22.28

on a normal distribution table, 65% of class is below mean + .4 sigma = 81.7+8.912 = 90.6
so his score is above 90.6

A) In statistics, parameters refer to numerical measures that describe a population, while statistics are numerical measures that describe a sample taken from the population.

In this case, the reported means and standard deviations are statistics. They are calculated based on the scores of the sample (students in the class) rather than the entire population.

B) To find the homework score of a student who scored higher than 65% of the class, we can use the concept of Z-scores.

First, we need to find the Z-score corresponding to the given percentage. The Z-score represents the number of standard deviations away from the mean a particular value is.

The formula to calculate the Z-score is:
Z = (X - μ) / σ

Where:
Z is the Z-score
X is the value (homework score in this case)
μ is the mean
σ is the standard deviation

To find the Z-score for being higher than 65% of the class, we need to find the Z-value corresponding to a cumulative probability of 0.65. This can be done using a Z-table or a statistical calculator.

Once we have the Z-score, we can rearrange the formula to find the homework score:
X = Z * σ + μ

Plug in the values:
μ = 81.7% (mean)
σ = 22.28% (standard deviation)
Z = The Z-score obtained from the cumulative probability of 0.65

Calculate X to find the homework score of the student who scored higher than 65% of the class.