Tips a pizza delivery driver, always trying to increase tips, runs an experiment on his next 40 deliveries. he flips a coin to decide whether or not to call a customer from his mobile phone when he is five minutes away, hoping this slight bump in customer service will lead to a slight bump in tips. after 40 deliveries, he will compare the average tip percentage between the customers he called and those he did not. 1. was the experiment randomized and replicated? 2. is this experiment blinded? 3. what are the experimental units and how did he randomize treatments?

option (a)

step-by-step explanation:

step 1:   take 2 number whose product equal to 25..

and sum of those two number are -10

step: 2 for example here if we take 5,5 are the number,,

5*5=25

and

5+5=10

but we need -10

so if we take   -5,-5

so -5*-5=25

and -5+(-5)=-10

s0

come the equation

replace -10x by these number

like -5x -5x+25

take common

x(x-5)-5(x-5)=0

(x-5)(x-5)=0

we need to divide the number of toy dinosaurs, 156, by the number of brothers, 4:

in order to estimate, we can use compatible numbers:

156 ÷ 4

  ↓

160   ÷ 4 = 40        

the correct answer is a).

answer: qc and de are congruent

hope i ! : )