The headteacher of a school wants to investigate opinions of pupils about meals sold in the canteen. she asks the first 20 people in the dinner queue their opinions.
explain why this is not a satisfactory method of selecting a sample of pupils.
describe how the headteacher could select a random sample of 20 students.

What value is equivalent to 5 + [5 × (4 + 2)]? a) 35 b) 45 c) 60 d) 110

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?