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In a study of 905 randomly selected children aged 15-17, 198 say they watch 3 or more hours of television per day. In a study of 503 randomly selected children aged 12-14, 97 reported they watch 3 or more hours of television per day. Is there a significant difference between age and watching television in teenagers

Respuesta :

Answer:

The calculated value Z = 0.063< 1.96 at 5% level of significance

Null hypothesis is accepted

There is no significant difference between age and watching television in teenagers

Step-by-step explanation:

Step(i):-

Given random sample size 'n' = 905

Given data 198 say they watch 3 or more hours of television per day.

Given random first sample size

                                  n₁ = 905

First sample proportion

           [tex]p_{1} = \frac{x_{1} }{n_{1} } = \frac{198}{905} = 0.2187[/tex]

Given random second sample size

                                  n₂ = 503

second sample proportion

           [tex]p_{2} = \frac{x_{2} }{n_{1} } = \frac{97}{503} = 0.1928[/tex]

Step(ii):-

Null Hypothesis : H₀

There is no significant difference between age and watching television in teenagers

Alternative Hypothesis :H₁

There is  significant difference between age and watching television in teenagers

Step(iii):-

Test statistic

[tex]Z = \frac{p_{1}-p_{2} }{\sqrt{PQ(\frac{1}{n_{1} }+\frac{1}{n_{2} } }) }[/tex]

Where

[tex]P = \frac{n_{1}p_{1} + n_{2} p_{2} }{n_{1}+n_{2} }[/tex]

[tex]P = \frac{905 X0.2187 + 503 X0.1928 }{905+503 }[/tex]

P =  0.2094    

Q = 1 - 0.2094 = 0.7906

[tex]Z = \frac{0.2187-0.1928}{\sqrt{0.2094 X0.7906(\frac{1}{905} +\frac{1}{503} } )}[/tex]

on calculation , we get

Z =   0.063

The critical value Z₀.₀₅ = 1.96

The calculated value Z = 0.063< 1.96 at 5% level of significance

Conclusion:-

Null hypothesis is accepted

There is no significant difference between age and watching television in teenagers