Problem #2

Table No Depression Depression All
Planned Vaginal Delivery \(b\) \(a\) \(a+b\)
row \(\frac{b}{a+b}\) \(\frac{a}{a+b}\)
col \(\frac{b}{b+d}\) \(\frac{a}{a+c}\)
Planned Caesarean Section Delivery \(d\) \(c\) \(c+d\)
row \(\frac{d}{c+d}\) \(\frac{c}{c+d}\)
col \(\frac{d}{b+d}\) \(\frac{c}{a+c}\)
All \(b+d\) \(a+c\) \(1\)
| Table                              | No Depression   | Depression      | All   |
|-------------------|------------------|------------------|------------------|
| Planned Vaginal Delivery           | $b$             | $a$             | $a+b$ |
| row                                | $\frac{b}{a+b}$ | $\frac{a}{a+b}$ |       |
| col                                | $\frac{b}{b+d}$ | $\frac{a}{a+c}$ |       |
| Planned Caesarean Section Delivery | $d$             | $c$             | $c+d$ |
| row                                | $\frac{d}{c+d}$ | $\frac{c}{c+d}$ |       |
| col                                | $\frac{d}{b+d}$ | $\frac{c}{a+c}$ |       |
| All                                | $b+d$           | $a+c$           | $1$   |

Problem #3

Table No Depression Depression All
Planned Vaginal Delivery \(b\) \(a\) \(a+b = 1-g\)
row \(1-e\) \(e\) \(1\)
col \(P(P_V | 1-P_D) = \frac{(1-P(P_D|P_V))P(P_V)}{1-P(P_D)} = \frac{(1-e)(1-g)}{b+d}\) \(P(P_V|P_D) = \frac{P(P_D|P_V)\cdot P_V}{P_D} = \frac{e \cdot (1-g)}{(a+c)}\)
Planned Caesarean Section Delivery \(d\) \(c\) \(c+d = g\)
row \(1-f\) \(f\) \(1\)
col \(P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d}\) \(P(P_C|P_D) = \frac{c}{a+c}\)
All \(b+d\) \(a+c\) \(1\)
| Table                              | No Depression                                                                     | Depression                                                                   | All         |
|----------------|---------------------------------|-------------------------------------------|----------------|
| Planned Vaginal Delivery           | $b$                                                                               | $a$                                                                          | $a+b = 1-g$ |
| row                                | $1-e$                                                                             | $e$                                                                          | $1$         |
| col                                | $P(P_V | 1-P_D) = \frac{(1-P(P_D|P_V))P(P_V)}{1-P(P_D)} = \frac{(1-e)(1-g)}{b+d}$ | $P(P_V|P_D) = \frac{P(P_D|P_V)\cdot P_V}{P_D} = \frac{e \cdot (1-g)}{(a+c)}$ |             |
| Planned Caesarean Section Delivery | $d$                                                                               | $c$                                                                          | $c+d = g$   |
| row                                | $1-f$                                                                             | $f$                                                                          | $1$         |
| col                                | $P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d}$     | $P(P_C|P_D) = \frac{c}{a+c}$                                                 |             |
| All                                | $b+d$                                                                             | $a+c$                                                                        | $1$         |

Problem #4

Table No Depression Depression All
Planned Vaginal Delivery \(b = 0.55\) \(a=0.15\) \(a+b = 1-g = 0.7\)
row \(1-e\) \(e = \frac{0.15}{0.70} = 0.21\) \(1\)
col \(P(P_V | 1-P_D) = \frac{(1-P(P_D|P_V))P(P_V)}{1-P(P_D)} = \frac{(1-e)(1-g)}{b+d} = \frac{0.79 \cdot 0.70}{0.75} = 0.74\) \(P(P_V|P_D) = \frac{P(P_D|P_V)\cdot P_V}{P_D} = \frac{e \cdot (1-g)}{(a+c)} = \frac{0.21 \cdot 0.70}{0.25} = 0.59\)
Planned Caesarean Section Delivery \(d = 0.20\) \(c=0.10\) \(c+d = g = 0.3\)
row \(1-f = 0.67\) \(f = \frac{0.10}{0.3} = 0.33\) \(1\)
col \(P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d} = \frac{0.67 \cdot 0.3}{0.75} = 0.27\) \(P(P_C|P_D) = \frac{c}{a+c} = \frac{0.10}{0.25} = 0.40\)
All \(b+d = 0.75\) \(a+c = 0.25\) \(1\)
| Table                              | No Depression                                                                                                           | Depression                                                                                                         | All               |
|-----------------|----------------------|-----------------|-----------------|
| Planned Vaginal Delivery           | $b = 0.55$                                                                                                              | $a=0.15$                                                                                                           | $a+b = 1-g = 0.7$ |
| row                                | $1-e$                                                                                                                   | $e = \frac{0.15}{0.70} = 0.21$                                                                                     | $1$               |
| col                                | $P(P_V | 1-P_D) = \frac{(1-P(P_D|P_V))P(P_V)}{1-P(P_D)} = \frac{(1-e)(1-g)}{b+d} = \frac{0.79 \cdot 0.70}{0.75} = 0.74$ | $P(P_V|P_D) = \frac{P(P_D|P_V)\cdot P_V}{P_D} = \frac{e \cdot (1-g)}{(a+c)} = \frac{0.21 \cdot 0.70}{0.25} = 0.59$ |                   |
| Planned Caesarean Section Delivery | $d = 0.20$                                                                                                              | $c=0.10$                                                                                                           | $c+d = g = 0.3$   |
| row                                | $1-f = 0.67$                                                                                                            | $f = \frac{0.10}{0.3} = 0.33$                                                                                      | $1$               |
| col                                | $P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d} = \frac{0.67 \cdot 0.3}{0.75} = 0.27$      | $P(P_C|P_D) = \frac{c}{a+c} = \frac{0.10}{0.25} = 0.40$                                                            |                   |
| All                                | $b+d = 0.75$                                                                                                            | $a+c = 0.25$                                                                                                       | $1$               |

P(Planned caesarean section delivery|Depression score <13) is \(P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d} = \frac{0.67 \cdot 0.3}{0.75} = 0.27\)

$P(P_C|1-P_D) = \frac{(1-P(P_D|P_C))P(P_C)}{1-P(P_D)} = \frac{(1-f)(g)}{b+d} = \frac{0.67 \cdot 0.3}{0.75} = 0.27$