Question

The growing seasons for a random sample of 34 US cities were recorded, yielding a sample mean of 188.1 days And the population standard deviation of 53.1 days. Estimate the true population mean of the growing season with 95% confidence

Answers

  1. Answer:

    (170.251 ; 205.949)

    Step-by-step explanation:

    Sample size, n = 34

    Sample mean, xbar = 188.1

    Population standard deviation, σ = 53.1

    Confidence level = 95% ; Zcritical at 95% = 1.96

    Using the confidence interval relation :

    Xbar ± standard Error

    Standard Error = Zcritical * σ/√n

    Standard Error = 1.96 * 53.1/√34

    Standard Error = 17.849

    Lower boundary = (188.1 – 17.849) = 170.251

    Upper boundary = (188.1 + 17.849) = 205.949

    (170.251 ; 205.949)

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