Claim: The mean systolic blood pressure of all healthy adults is less than 124 mm Hg . Sample data: For 281 healthy adults, the mean systolic blood pressure level is 122.64 mm Hg and the standard deviation is 15.33 mm Hg . Complete parts (a) and (b). a. Express the original claim in symbolic form. Let the parameter represent a value with respect to systolic blood pressure of a healthy adult. (Type an integer or a decimal. Do not round.) b. Identify the null and alternative hypotheses.

Determine whether the following statement is true or false. To construct a confidence interval about the mean, the population from which the sample is drawn must be approximately normal. This statement is

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) \( \begin{array}{l}\text { (a) Obtain a point estimate for the population proportion of adults in the country aged } 18 \text { and older who have donated blood in the past two years. } \\ \text { (Round to three decimal places as needed.) }\end{array} \)

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.

At a festival, one game involves guessing the number of candies in a plastic jar. The following data represents the guesses that people made during one hour at the festival. Complete the frequency table for this data. \[ 1382,1211,1354,1171,1058,1472,1132,1090,1132,1443,1163,1274,1112,1266,1254,1174 \]

Determine the point estimate of the population mean and margin of error for the confidence interval. Lower bound is 21 , upper bound is 29 . The point estimate of the population mean is 1