On the SAT exam, a total of 25 minutes is allotted for students to answer 20 math questions without the use of a calculator. A guidance counselor would like to know if the students in his school are prepared to complete this portion of the exam in the time allotted. To investigate, the counselor selects a random sample of 35 students and administers this portion of the test. The students are instructed to turn in their test as soon as they have completed the questions. The mean amount of time taken by the students is 23.5 minutes with a standard deviation of 4.8 minutes. The counselor would like to know if the data provide convincing evidence that the true mean amount of time needed for all students of this school to complete this portion of the test is less than 25 minutes. What are the appropriate hypotheses?

H0: μ = 23.5 versus Ha: μ < 23.5, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 23.5 versus Ha: μ > 23.5, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 25 versus Ha: μ < 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 25 versus Ha: μ > 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam

Mean is the ratio of the sum of all the observations and the total number of observations in a data set. The standard deviation is a statistic that measures the dispersion of a data set relative to its mean and is calculated as the square root of the variance.

For the above suituation,

There are 20 math questions to be answered in 25 minutes.

After investigation with 35 students, the meantime needed for them is 23.5 and the standard deviation is 4.8.

From the above information, we can say that the hypothesis, H0: μ = 25 versus Ha: μ < 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam.

Hence we can conclude that the hypothesis (C) is the correct answer.

Learn more about mean and standard deviation here

https://brainly.com/question/475676

#SPJ2