When a random sample is selected from a population, the sample mean is usually not equal to the population mean due to sampling error. On average, the discrepancy between the sample mean and population mean is predicted by: the standard error. the expected value. the'mean of the population. the standard deviation of the population. the standard deviation of the sample.

Ork Explain why the \( t \)-distribution has less spread as the number of degrees of freedom increases. Choose the correct answer below. A. The \( t \)-distribution has less spread as the degrees of freedom increase because, as \( n \) increases, 2 of 8 posints information is known about \( \sigma, 9.2 .49 \) by the law of large numbers. B. The \( t \)-distribution has less spread as the degrees of freedom increase because, as \( n \) increases, s becomes closer to \( \sigma \) by the law of large numbers. C. The \( t \)-distribution has less spread as the degrees of freedom increase because, for large values of \( n \), \( n \geq 30 \), the \( t \)-distribution and the normal distribution are the sam D. The \( t \)-distribution has less spread as the degrees of freedom increase because the variability introduced into the \( t \)-statistic becomes greater as \( n \) increases.

A survey of 2283 adults in a certain large country aged 18 and older conducted by a reputable polling organization found that 406 have donated blood in the past two years. Complete parts (a) through (c) below. Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2) \( \begin{array}{l}\text { (a) Obtain a point estimate for the population proportion of adults in the country aged } 18 \text { and older who have donated blood in the past two years. } \\ \text { (Round to three decimal places as needed.) }\end{array} \)

Homework Determine the point estimate of the population proportion, the margin of error for the following confidence interval, and the number of individuals in the sample with the specified characteristic, \( x \), for the sample size provided. Lower bound \( =0.529 \), upper bound \( =0.831, n=1500 \) (Round to the nearest thousandth as needed.) The margin of error is \( \square \). (Round to the nearest thousandth as needed.)

Derk Determine the point estimate of the population proportion, the margin of error for the following confidence interval, and the number of individuals in the sample with the specified characteristic, \( x \), for the sample size provided. Lower bound \( =0.529 \), upper bound \( =0.831, n=1500 \) The point estimate of the population proportion is 0.68 . (Round to the nearest thousandth as needed.) The margin of error is (Round to the nearest thousandth as needed.)

What is a scatter plot?