Answer:
A recent report estimated that 25% of all college students in the United States have a sexually transmitted disease (STD). The director of the campus health center believes that the proportion of students with STDs is higher at their campus.
According to the American Heart Association guidelines, the daily maximum amount of sugar a teenager should have is 4 teaspoons. The parents of a local high school have expressed concerns that the average daily sugar intake of their students is higher than these guidelines and have been pressuring school officials to limit unhealthy snack and beverage choices offered in the cafeteria and student store.
Step-by-step explanation:
The first two researches involve the single sample compared to mean of population.
The 3rd and 4th research involves comparing samples of men and women that is two individual groups.
Solution:
1. Cost of a new Violin that is bought by the musician = $ 2900
Monthly interest charge = 3.35 %
If you will find the compound interest or simple interest for a month, they both will be same for a month.
Simple interest =


Interest paid at the end of first month = $ 97.15
2. Loan Amount = $ 3,500
Annual interest = 8 %
Time period = 2 years= 24 months
As , we have to find the total payback for two years, at 8% annual interest with monthly payments .we will use the formula of Amount in terms of compound interest here.
Formula for Amount
Amount= ![Principal (1 +\frac{Rate}{100})^{time}]](https://tex.z-dn.net/?f=Principal%20%281%20%2B%5Cfrac%7BRate%7D%7B100%7D%29%5E%7Btime%7D%5D)
![=3500 \times [(1+\frac{8}{1200})^{24}]\\\\ = 3500 \times [(1.0066)^{24}]\\\\= 3500 \times 1.1710 \\\\ =4098.58](https://tex.z-dn.net/?f=%3D3500%20%5Ctimes%20%5B%281%2B%5Cfrac%7B8%7D%7B1200%7D%29%5E%7B24%7D%5D%5C%5C%5C%5C%20%3D%203500%20%5Ctimes%20%5B%281.0066%29%5E%7B24%7D%5D%5C%5C%5C%5C%3D%203500%20%5Ctimes%20%201.1710%20%5C%5C%5C%5C%20%3D4098.58)
Total payback after 2 years = $ 4098.58
I hope this helps you
5-2x=15
5-15=2x
2x= -10
x=-5