A survey of licensed drivers inquired about running red lights. One question asked, "Of every 10 motorists who run a red light, about how many do you think will be caught?" The mean result for 880 respondents was
¯x= 1.92. Suppose we know that σ = 1.83. Compute a 95% confidence interval for the mean opinion in the population of all licensed drivers. (Round your answer to the nearest hundredth.)

Respuesta :

Answer: (0.79, 3.05 )

Step-by-step explanation:

Confidence interval for the population mean:

[tex]\overline{x}\pm z^c\dfrac{\sigma}{\sqrt{n}}[/tex]

, where [tex]\overline{x}[/tex] = Sample mean

[tex]\sigma[/tex] = population standard deviation

n= sample size.

[tex]z^c[/tex] = Critical z value for confidence interval c.

As per given:

n= 10

[tex]\overline{x}=1.92[/tex]

[tex]\sigma=1.83[/tex]

Critical z-value for 95% confidence = 1.96

A 95% confidence interval for the mean opinion in the population of all licensed drivers:-

[tex]1.92\pm (1.96)\dfrac{1.83}{\sqrt{10}}\\\\=1.92\pm1.134\\\\= (1.92-1.134,\ 1.92+1.134)\\\\\approx(0.79,\ 3.05 )[/tex]

Hence, a 95% confidence interval for the mean opinion in the population of all licensed drivers = (0.79, 3.05)

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