Can someone please help me.

4. a spring scale is constructed so that each 0.10-n increment is separated by 0.50 cm. what spring constant is necessary for the scale to be accurate? -1.0n/cm -0.10n/cm -9.8 n/cm -0.20n/cm

anyone? find the second, fifth, and ninth terms of a sequence where the first term is 65 and the common difference is -7. 72, 93, 121 72, 79, 86 58, 37, 9 58, 51, 44

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.