91影视

x₁ = 29, n₁ 189, x₂=32, andn₂=149.

Let x₁ be the number of winning bids above the item鈥檚 anticipated value by the super experienced group and x₂ be the number of winning bids above the item鈥檚 anticipated value by the less-experienced group.

Here we have informed that 29 of 189 winning bids were above the item鈥檚 anticipated value by the super-experienced group, and 32 of the 149 winning bids were above the item鈥檚 expected value by the less-experienced group.

that means we have x₁ = 29, n₁ 189, x₂=32, andn₂=149.

By definitions, the estimate of the true proportion of super-experienced bidders who fall prey to the winner鈥檚 curse (p鈧�) is given as

$\underline{P_1}=\frac{x_1}{n_1}$

$=\frac{29}{189}$

$\underline{P_1}=0.153$

By definitions, the estimate of the true proportion of less-experienced stab who fall prey to the winner鈥檚 curse (p鈧�) is given as

$\underline{P_2}=\frac{x_2}{n_2}$

$=\frac{32}{149}$

$\underline{P_2}=0.215$

We know that a (1-伪)% confidence interval to estimate the difference between the population proportions (P₁ 鈥� P₂) is defined as

(P₁ 鈥� P₂)$+z_{\frac{a}{2}}\sqrt{\frac{p_1{q}_1}{n_1}+\frac{p_2{q}_2}{n_2}}$

$z_{\frac{a}{2}=}{z}_{\frac{0.1}{2}}$

role="math" localid="1652709934887" $=z_{0.05}$

$z_{\frac{a}{2}}=1.645$

Thus the 90% confidence interval estimates the difference between the population proportions.

= (P₁ 鈥� P₂) 卤 1.645 脳$\sqrt{\frac{p_1{q}_1}{n_1}+\frac{p_2{q}_2}{n_2}}$

(P₁ 鈥� P₂) is defined as = ( 0.153 鈥� 0.215) 卤 1.645 脳role="math" localid="1652710155075" $\sqrt{\frac{0.153脳\left(1-0.153\right)}{189}+\frac{0.215脳\left(1-0.215\right)}{149}}$

= - 0.061 卤 1.645 脳

= - 0.061 卤 0.070

= ( - 0.131, 0.009 )

Therefore the 90% confidence interval to estimate the difference between the population proportions (p₁ 鈥� p₂ ) is obtained as (-0,131, 0.009).

From part (C), we are 90% confident that we estimate the difference between the population proportions. (P鈧�-P₂) the between -0.131 and 0.009.

Here we observe that zero passes through the 90% confidence interval.

That means there is no evidence of the difference between the population proportions.

So, there is no evidence to conclude that the bid experience impacts the likelihood of the winner鈥檚 curse occurring.