How many four-digit positive integers are multiples of 3?

Customers at an ice-cream shop took a survey .the results showed that 144 customers rated the shop as being "very satisfactory ."this number represented 45%of the total nunber of customers who took the survey

Apple pie is removed from 350 degree oven. temperature of the pie t minutes after being removed id given by the function t(t)=72+268e-0.068t

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