Which phrase describes an unknown or changeable quantity?

a. 4 quarts in a gallon
b. a score of 27 points
c. 80 miles per hour
d. the number of different colors on the page

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population, find the population standard deviation, o.79828588912497

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample

Which is the focus of a parabola with equation y2=4x