A set of final examination grades in an introductory statistics cours is normally distributed, with a mean of 73 and a standard deviation 8 . (a) What is the probability that a student scored below 91 on this exam (b) What is the probability that a student scored between 65 and 89 ? (c) The probability is \( 5 \% \) that a student taking the test scores higher th what grade? (d) If the professor grades on a curve (i.e., gives A's to the top \( 10 \% \) of class, regardless of the score), are you better off with a grade of 81 this exam or a grade of 68 on a different exam, where the mean is 6 and the standard deviation is 3? Show your answer statistically and explain.

4.2PS-9 Car Survey In a survey of 2,400 people who owned a certain type of car, 960 said they would buy that type of car again. What percent of the people surveyed were satisfied with the car?

In a class, there are 750 learners in 1st year, 420 learners in 2 nd year. Draw a pie graph to represent the numbers of learners in these groups.

1. Estas interesado en detectar diferencias en tiempo promedio de programación de comerciales en horario estelar. Un estudio similar detecto una desviación estándar de 30 minutos. Quisieras calcular una muestra con una confiabilidad del \( 95 \% \) y un error máximo tolerable de 5 minutos en tus estimaciones. ¿Qué tan grande tiene que ser tu muestra?

a) Copy and complete the equation of the line of best fit below. Give any decimals in your answer to 1 d.p.

men are randomly selected and tested. Among the men, 563 have color blindness, and among the wo lindness than women at an \( \alpha=0.05 \) level of significance. Round all values to at least 4 decimal places.