In a random sample of 3941 Americans 18 and older, \( 29 \% \) of participants reported they were unmarried. Use the rule of thumb to calculate the margin of error for a \( 95 \% \) confidence interval. Round to the nearest hundredth, if necessary.

The probability of committing a Type I error: is solely determined by the size of the treatment effect. cannot be controlled by the experimenter. is determined by the alpha (a) level that one chooses. is determined by the beta ( \( \beta \) ) level one chooses. is determined by the sample size that one chooses.

By selecting a smaller alpha level, a researcher is: attempting to make it easier to reject the null (HO). attempting to make it easier to reject the alternative (H1). reducing the risk of a Type I error. attempting to decrease the standard error.

The null hypothesis: predicts that the treatment will have no effect. predicts that the treatment will have an effect. is denoted by the symbol H1. is always stated in terms of sample statistics.

A researcher rejects the null hypothesis only if the obtained statistical results show: that it is likely that the null is true. that it is unlikely that the null is true. that it is likely that the alternative hypothesis is false. that is unlikely that the alternative hypothesis is false.

A researcher risks a Type I error: anytime HO is rejected. anytime H 1 is rejected. anytime HO is accepted. anytime the sample size is increased.