Answer:
89
Step-by-step explanation:He bought 89 items because 20 + 3 is 23, 23 + 12 is 35, 35 + 11 is 46, 46 + 24 is 70, and 70 + 11 is 89.
Answer:
Maridel wants to find out how many of her classmates plan to come to the next football game. There are 800 students in her school. She selects a sample of the population by putting the names of every student into a bag and drawing out 100 names.
Which statement(s) describe her sampling method? Check all that apply.
A) Her method will produce a biased sample.
<u>B) Her method will produce a valid sample.</u>
<u>C) Her method will produce a random sample.</u>
<u>D) Her method will produce a representative sample.</u>
E) Her method will produce an invalid sample.
Step-by-step explanation:
Answer:
4.979044478499338 × 10²⁶
Step-by-step explanation:
Combination can be used to determine the number of ways the mice can be selected for the drugs (A, B) and the control group.
Combination factorial is define by ⁿCr = 
21 group of mice receiving Drug A can be selected in ⁶⁰C₂₁ = 
(60 - 21 = 39 ) mice remained for selection of 21 mice for the second drug
Drug B 21 mice can be chosen with ³⁹C₂₁ = 
( 39 - 21 = 18) remained for control with ¹⁸C₁₈ =
The number of ways the mice can be chosen for drug A, drug B and the control = ⁶⁰C₂₁ × ³⁹C₂₁ × ¹⁸C₁₈ =
×
×
= 4.979044478499338 × 10²⁶