How do I write 3.1 x 10-⁶ +1.9 x 10-³ in scientific notation form?

In a sample of 200 residents of georgetown county, 120 reported they believed the county real estate taxes were too high. develop a 95 percent confidence interval for the proportion of residents who believe the tax rate is too high. (round your answers to 3 decimal places.) confidence interval for the proportion of residents is up to . would it be reasonable to conclude that the majority of the taxpayers feel that the taxes are too high?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?