Answer: u= ( 4342.08, 5145.92).
Step-by-step explanation: the population mean is estimated using the sample by the formulae assuming a 95% confidence level
u = x' + Zα/2 * (√σ/n) or x' - Zα/2 * (√σ/n)
u = estimated population mean
x' = sample mean = 4744
n = sample size =8
σ = sample standard deviation. = 580
α = level of significance = 1- confidence level = 1-0.95= 0.05
Zα/2 = z score from the normal distribution table for a 2 tailed test = 1.96
First boundary value for interval
u = 4744 + 1.96 ( 580/√8)
u = 4744 + 1.96 * (205.0609)
u = 4744 + 401.92
u = 5145.92
Second boundary value for interval
u = 4744 - 1.96 ( 580/√8)
u = 4744 - 1.96 * (205.0609)
u = 4744 - 401.92
u = 4342.08
Thus the confidence interval for population mean is
u= ( 4342.08, 5145.92).
Te difference of 2 standard deviation of a population n1 & n2 is given by the formula:
sigma (difference)=√(sigma1/n1 + sigma2/n2), Plug:
sigma(d)= √(49/100 + 36/50)
Sigma(d=difference) =1.1
Since 1cm represents 4 meters then .5cm would represent 2 meters.
To rent 7 movies, he needs 2(7) + 12 = $26.
But he has only $10. So he needs more 26 - 10 = $16.
