The population standard deviation for the age of a certain University students is 10 years. If we want to be 90% confident that the sample mean age is within 3 years of the true population mean age of the University students, then how many randomly selected students must be surveyed?

An architect builds a model of a park in the shape of a rectangle. the model is 40.64 centimeters long and 66.04 centimeters wide. one inch equals 2.54 centimeters. use the ratio table to find the ratio of the length to the sum of the length and width in inches and in simplest form. length 40.64 width 66.04 a. 8: 21 b. 13: 21 c. 21: 13 d. 21: 8