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Test di ipotesi Confronto tra medie e proporzioni

Test di ipotesi Confronto tra medie e proporzioni

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<strong>Test</strong> t per campioni in<strong>di</strong>pendenti<br />

1 =<br />

1 =<br />

1 =<br />

Nati da madri<br />

non fumatrici 1 1 1<br />

Nati da madri<br />

fumatrici<br />

n 8143<br />

1 . 3424 x 6 . 474 s<br />

n 5065 x 3241 3241.<br />

6 s 476 476.<br />

5<br />

2 =<br />

2 =<br />

( x1<br />

− x2<br />

)<br />

t =<br />

( 3424.<br />

1−<br />

3241.<br />

6 )<br />

s<br />

⎛<br />

⎜<br />

⎝<br />

1<br />

+<br />

1<br />

2<br />

p<br />

⎝ n n1<br />

n n2<br />

⎞<br />

⎟<br />

⎠<br />

t<br />

=<br />

8.<br />

51<br />

=<br />

2 =<br />

t = t<br />

8143+<br />

5065−2<br />

182.<br />

5<br />

8.<br />

51<br />

p = P ( t ≥ 21.<br />

4 ) + P ( t ≤ −21.<br />

4 ) = 0.<br />

00+<br />

0.<br />

00 =<br />

p = 0.00 < 0.05 ⇒ si rifiuta l’<strong>ipotesi</strong> nulla<br />

=<br />

21.<br />

4<br />

0.<br />

00<br />

13206

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