Question

17. A major airline company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that on the average 18% of the company airplanes have arrived late. In a random sample of 1,250 airplanes, 250 airplanes have arrived late. If we are conducting a hypothesis test of a single proportion to determine if the proportion of late arrivals has increased: What is the correct statement of null and alternative hypothesis?
A. H₀: p <.18 and H_A: p ³.18
B. H₀: p £.18 and H_A: p >.18
C. H₀: p =.18 and H_A: p ¹ .18
D. H₀: p >.18 and H_A: p £.18
E. H₀: p £.20 and H_A: p >.20

19. What value(s) of alpha would we reject H₀ for m greater than 10 if    = 11, s =2 and n=36?
A. .05 and .01
B. .01 and .001
C. .05 and .10 but not .01
D. All of the above
E. None of the above

23. In simple regression analysis the quantity that gives the amount by which Y (dependent variable) changes for a unit change in X (independent variable) is called the
A. Coefficient of determination
B. Standard error
C. The Y intercept of the regression line
D. Correlation coefficient
E. Slope of the regression line

Answer 1

This is binomial proportion testing

(17)

The historical data shows that 18% planes were late. Therefore null hypo will be p = 0.18

We have to test the late arrivals have increased. Alternative hypo will be p > 0.18

Final ans: B. H₀: p = .18 and H_A: p > .18

(19)

The question is not clear as to what paramter testing has to be conducted. But I am assuming It is student's t - dist and testing is for population mean

Test Statistic =

Test Stat = =

p - value =

p - value = 0.002474

We reject null hypo when p - value <

According to our given option p - value < 0.01, 0.05, 0.10. This best fits the option A

Final ans: A. .05 and .01​​​​​​​

(23)

The equation of regression line is

where m is the slope. this is the quantity that gives the amount by which Y (dependent variable) changes for a unit change in X (independent variable).

Final Ans: E. Slope of the regression line