In interval estimation, the t distribution is applicable only when a. the population has a mean of less than 30. b. the sample standard deviation (s) is given instead of the population standard deviation (σ). c. the variance of the population is known. d. the standard deviation of the population is known. e. we will always use the t distribution

Consider the following estimates from the early 2010s of shares of income to each group. country poorest 40% next 30% richest 30% bolivia 10 25 65 chile 10 20 70 uruguay 20 30 50 1.) using the 4-point curved line drawing tool, plot the lorenz curve for bolivia. properly label your curve. 2.) using the 4-point curved line drawing tool, plot the lorenz curve for uruguay. properly label your curve.

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.

Paul can type 60 words per minute and jennifer can type 80 words per minutes.how does paul's typing speed compare to jennifer's