college algebra

posted by .

3. Students in an English class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. The average score S(t), in percent, after t months was found to be given by
S(t) = 68 − 20 log (t + 1), t ¡Ý 0.
What was the average score when they initially took the test, t = 0?
Round your answer to a whole percent, if necessary.a)Answer:
Show your work in this space:
What was the average score after 4 months? after 24 months?
Round your answers to two decimal places.b)Answer:Show your work in this space:

After what time t was the average score 50%?Round your answe

  • college algebra -

    when t = 0
    S(0) = 68 - 20log(1) = 68

    when t= 4
    S(4) = 68 - 20log(5) = 54.02... or 54

    etc.

    for score to be 50
    50 = 68 - 20log(t+1)
    log(t+1) = 18/20 = .9
    t+1 = 10^.9
    t = 10^.9 - 1 months
    = 6.943 or appr. 7 months

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Statistics

    In Professor Smith's statistics course, the correlation between students' total scores before the final exam and their final exam scores is r = 0.67. The pre-exam totals for all students in the course have a mean of 275 and a standard …
  2. algebra

    students in a biology class just took a final exam. a formula for predicting the average exam grade on a similar test t months later is. s(t)=78-15log(t+1) (a)find the students average score when they first took the final exam. (b)what …
  3. statistics

    Suppose that the mean score of an exam was 77 when taken 30 students took it on time with a standard deviation of 2. A makeup of the same exam is given to 6 students. The retakes averaged a score of 83 with a standard deviation of …
  4. statistics

    Suppose that the mean score of an exam was 77 when taken 30 students took it on time with a standard deviation of 2. A makeup of the same exam is given to 6 students. The retakes averaged a score of 83 with a standard deviation of …
  5. college algebra

    Students in an English class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. The average score S(t), in percent, after t months was found to be given by S(t) = 68 - 20 log (t+1), t > 0
  6. Algebra

    Students in an English class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. The average score S(t), in percent, after t months was found to be given by . a) What was the average score when …
  7. College Algebra

    Students in an English class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. The average score S(t), in percent, after t months was found to be given by . a) What was the average score when …
  8. VNS,Math

    Mr. Bobby bought 50 shares at $60, and 2 months later purchased 25 shares a $56.at what price should he purchase 25 additional shares in order to have an average price $58 per share?
  9. math (algebra)

    In Professor Tuffguy's mathematics class, 36 students took the final exam. If the average passing grade was 78, the average failing grade was 60, and the class average was 71, how many of these 36 student passed the final?
  10. Algebra

    Over 350 students took a college calculus final exam. the scores of the students follow a normal distribution. using the information given below, determine the mean and the standard deviation for the students'scores. Give your answers …

More Similar Questions