All numbers that only have one and itself as factors are prime. Therefore, to tell if a number is prime simply find it's factors. If it has more than two factors than it is not a prime number.
<u>Answer:</u>
<h2>Romania</h2>
U.S: 272,648,000÷9,364,520= 29.12
<u><em>Step-by-step</em><em> </em><em>explaination</em></u>
US: 29.12 people per square km
Romania: 22,609,000÷237,391= 95.24
Romania: 95.24 people per square km
Ghana: 18,339,000÷237,553= 77.20
Ghana: 77.2 people per square km
0.7=7/10
0.8=8/10
0.75=3/4 this is between 0.7 and 0.8
