Author: Anonymous

A customer-service department uses hold time x, in minutes, to predict satisfaction score y. The regression equation is: ŷ = 88.314 − 6.205x For x = 7.2 minutes, what is the predicted satisfaction score?

A researcher uses hours of sleep to predict reaction-time score. Excel regression output gives: Multiple R = 0.522R Square = 0.272Significance F = 0.121Intercept = 38.600Sleep Hours coefficient = 2.180 Using α = 0.10, which conclusion is correct?

A two-sample mean test has H₁: μ₁ < μ₂ and α = 0.08. Which Excel formula gives the correct left critical value?

Find the z-value such that the area to the right of z is 0.035. (round to 3 decimals)

A student success office studies whether weekly tutoring hours predict final exam scores. Excel regression output gives the following: Multiple R = 0.918R Square = 0.843Significance F = 0.006Intercept = 54.327Tutoring Hours coefficient = 4.812 Which statement is correct?

A standardized reading score is normally distributed with mean μ = 72 and standard deviation σ = 8. What is the probability that a randomly selected student scores below 84?

A sales director predicts monthly sales Y using website visits X₁ and number of sales calls X₂. Excel output gives: Multiple R = 0.935R Square = 0.874Adjusted R Square = 0.846Significance F = 0.002Intercept = 14.775X₁ coefficient = 0.026X₂ coefficient = 1.384 Which statement correctly interprets R Square?

A city planner uses average household income X₁ and average commute distance X₂ to predict neighborhood retail spending Y. Excel output gives: Multiple R = 0.781R Square = 0.610Adjusted R Square = 0.557Significance F = 0.064Intercept = 12.340X₁ coefficient = 0.009X₂ coefficient = −0.415 Using α = 0.05, which conclusion is correct?

Let X follow a Poisson distribution with mean λ = 4.9. Write the Excel formula/function to compute: P(X >= 6) Use the complement of the cumulative distribution if appropriate.

A political polling firm compares the proportion of registered voters supporting a ballot measure in County 1 and County 2. Let p₁ = support proportion in County 1. Let p₂ = support proportion in County 2. The firm claims that the support proportion in County 1 is less than the support proportion in County 2. Which setup is correct?