Georgianna claims that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons. We have a random sample of 20 children from the city, with a mean of 4.6 years of piano lessons and a standard deviation of 2.2 years. Required:Explicitly state and check all conditions necessary for inference on these data.

Respuesta :

Answer:

The  condition  are

           The  Null hypothesis is  [tex]H_o : \mu = 5[/tex]

           The  Alternative hypothesis is  [tex]H_a : \mu < 5[/tex]

The  check revealed that

             There is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons

Step-by-step explanation:

From the question we are told that

     The  population mean is  [tex]\mu = 5 \ year[/tex]

      The sample size is  n =  20

      The sample mean is  [tex]\= x = 4.6 \ years[/tex]

       The  standard deviation is [tex]\sigma = 2.2 \ years[/tex]

   The  Null hypothesis is  [tex]H_o : \mu = 5[/tex]

   The  Alternative hypothesis is  [tex]H_a : \mu < 5[/tex]

So i will be making use of  [tex]\alpha = 0.05[/tex] level of significance to test this claim

    The critical value of  [tex]\alpha[/tex] from the normal distribution table is  [tex]Z_\alpha = 1.645[/tex]

 

Generally the test statistics is mathematically evaluated as

                 [tex]t = \frac{\= x - \mu}{ \frac{\sigma }{\sqrt{n} } }[/tex]

substituting values

                 [tex]t = \frac{ 4.6 - 5}{ \frac{2.2}{\sqrt{20} } }[/tex]

                [tex]t = -0.8131[/tex]

Looking at the value of  t and [tex]Z_{\alpha }[/tex] we see that  [tex]t < Z_{\alpha }[/tex] so we fail to reject the null hypothesis  

  This implies that there is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons.