# 8.12: Chapter Solution (Practice + Homework)

- Page ID
- 6079

**136**.

- \(\overline x = $568,873\)
- \(CL = 0.95\) \(\alpha = 1 – 0.95 = 0.05\) \(z_{\frac{\alpha}{2}}=1.96\)

\(E B M=z_{0.025} \frac{\sigma}{\sqrt{n}}=1.96 \frac{909200}{\sqrt{40}}=\$ 281,764\) - \(\overline x − EBM = 568,873 − 281,764 = 287,109\)

\(\overline x + EBM = 568,873 + 281,764 = 850,637\) - We estimate with 95% confidence that the mean amount of contributions received from all individuals by House candidates is between $287,109 and $850,637.

**139**.

Higher

**140**.

It would increase to four times the prior value.

**141**.

No, It could have no affect if it were to change to \(1 – p\), for example. If it gets closer to 0.5 the minimum sample size would increase.

**142**.

Yes

**143**.

- No
- No