Answer: 151
Step-by-step explanation:
if prior population proportion is unknown , then the formula is used to find the sample size :

, where
= Two tailed critical value for significance level of 
E = Margin of error.
Given : margin of error = 8%= .08
For 95% confidence level , two tailed critical value = 1.96
Now, the required sample size :

Hence, the size of the sample needed = 151.
Answer:
$ 2,600 was invested at 4% and $ 3,600 was invested at 9%.
Step-by-step explanation:
Given that in investing $ 6,200 of a couple's money, a financial planner put some of it into a savings account paying 4% annual simple interest, and the rest was invested in a riskier mini-mall development plan paying 9% annual simple interest, and the combined interest earned for the first year was $ 428, to determine how much money was invested at each rate, the following calculation must be performed:
3000 x 0.04 + 3200 x 0.09 = 408
2500 x 0.04 + 3700 x 0.09 = 433
2600 x 0.04 + 3600 x 0.09 = 428
Therefore, $ 2,600 was invested at 4% and $ 3,600 was invested at 9%.
Answer:
0
Step-by-step explanation:
9) x= -7
10) x= 10
11) x= 5
12) x= 6
13) x= 4
14) x= -9
15) x= 3
16) x= 9
sorry it took so long! hope this helps!! :)