1.Using data froma simple random sample of 40 US adultsto construct a 95%confidence interval estimate for the population proportion of US adults who smoke,the critical valueused to calculate the margin of erroris:

=1.645

= 2.023with df =39 (two-tail)

=1.96

=1.685withdf=39(one-tail)

2.A one-tailed hypothesis test is conducted at= 0.05 level of significance resulting in a P-value = 0.032. Which of the following conclusion isvalid?

The nullhypothesisis rejectedand a type Ierror is possible

The probability of rejecting the null hypothesis is 0.032

The null hypothesis is rejected and the alternative hypothesis should be true

The null hypothesis is rejected and it must be false