Answer the following by using the z-table from class. The life of a 9-volt battery is normally distributed with a mean of l = 2000 hours and a standard deviation of o = 40 hours. What is the proportion of batteries with an average life of 2100 hours or more? (enter answer as a percent rounded to the nearest hundredth as needed)

The following histogram shows the amount of Potassium (in milligrams (mg) perserving) in 39 boxes of cereal. Use this histogram to answer the following questions. Image(a) What is the shape of this data?(b) What percent of the tested cereals have less than 80mg of potassium per serving?(c) What are the highest potassium levels in these cereals? Be as accurate as youare able.(d) What are the lowest potassium levels in these cereals? Be as accurate as you areable.

Suppose that the correlation between height and IQ in children is +0.70. What proportion (or percent) of the variability in IQ can be explained by the relationship with height?​ Select one: a. 44% b. 51% c. 70% d. 49%

Arsenic is toxic to humans and people can be exposed to it through contaminated drinking water, food, dust, and soil. Scientists have devised a non-invasive way to measure a person's level of arsenic poisoning: by examining toenail clippings. In a recent study, scientists measure the level of arsenic (in mg/kg) in toenail clippings of 8 people who lived near a former arsenic mine in Great Britain. The following levels are recorded. 0.8, 1.9, 2.7, 3.4, 3.9, 7.1, 11.9, 26.0 Below are the summary statistics of the data. min Q1 median Q3 max sd n mean 0.8 2.5 3.65 8.3 26 7.2125 8.368041 8 Suppose the 8 people examined were randomly sampled from residents near the former arsenic mine. Is it legitimate to construct a 95% confidence interval for the mean level of arsenic (in mg/kg) in toenail clippings for residents near the former arsenic mine using a t-distribution? Explain briefly.