Answer:

Step-by-step explanation:
-For a known standard deviation, the sample size for a desired margin of error is calculated using the formula:

Where:
is the standard deviation
is the desired margin of error.
We substitute our given values to calculate the sample size:

Hence, the smallest desired sample size is 23
We are given
piggy bank has nickels , dimes and quarters
Let's assume
number of nickels =n
every two nickels there are 3 dimes
so, number of dimes are


every two dimes that are 5 quarters there
so, number of quarters are


so, total number of coins = number of nickels + number of dimes +number of quarters
total number of coins =n+1.5n+3.75
there are 500 coins
so, we get

now, we can solve for n

divide both sides by 6.25
so, we get

number of dimes is 1.5n


number of quarters is 3.75n


so,
Number of nickels =80
Number of dimes =120
Number of quarters =300............Answer
Answer: Anna could buy 5 sweatshirts for $75.
Step-by-step explanation:
lets figure out the price of one sweatshirt.
45/3 = 15
one sweatshirt is $15
5*15=75
so 5 sweatshirts cost $75
2x3=6x3=18 u always do PEMDAS,
Answer:
Step-by-step explanation:
a) For a prime numbers we have array with 2 rectangulars R1: a=1 and b=prime number; R2: a=prime number and b=1. Both has the same are, that prime number.
b) For a composite number which are not square number we have rectanular array with even numbers of ractangulars. For example, number 6.
R1: a=1,b=6; R2: a=2,b=3; R3: a=3, b=2; R4: a=6,b=1. Each rectangular has the same area, 6.
c) The square number we alway have te odd number of rectanulars, because of the square a=x,b=x can not be simetric. For example 16.
R1: a=1,b=16; R2: a=2 , b=8; R3: a=4,b=4; R4: a=8, b=2; R5:a=16,b=1.Each rectangular has the same area, 16.