The average number of weekly social media posts varies jointly with the poster's yearly income (In thousands) and inversely with their age in years. If a 60-year-old person with an income of $100,000 posts an average of 300 times in a week, what is the value of k?
k = 100
k = 300
k = 180
k =225

Solve for the equation. 4x - 13 = 2x + 9

Arandom sample of 45 observations results in a sample mean of 68. the population standard deviation is known to be 23 a. compute the margin of error at a 959% confidence interval. b. compute the 95% confidence interval for the population mean c. compute the 90% confidence interval for the population mean. d. compute the 75% confidence interval for the population mean

Need answer asap (see image) (20 points)