stat

posted by .

the average number of pushups a United States Marine does daily is 300, with a standard deviation of 50. A random sample of 36 marines is selected. What is the probability that the sample mean is at most 320 push-ups?

With a mean of 300, you are looking for a sample using a Standard Error of the Mean (SE). (The SE functions the exact same way for a distribution of means as the SD does for a distribution of raw scores.)

SE = SD/(sq.rt.of N) = 50/6

Once you can determine how many SE above the mean the value of 320 is, use the "Area Under the Normal Distribution" table in the back of your statistics book to find the probability.

I hope this helps. Thanks for asking.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. statistics

    The scores of students on the ACT college entrance examination in a recent year had a normal distribution with a mean of 18.6 and a standard deviation of 5.9. A simple random sample of 50 students who took the exam is selected for …
  2. Statistics

    he Oil Price Information Center reports the mean price per gallon of regular gasoline is $ 3.79 with a population standard deviation of $ 0.18. Assume a random sample of 40 gasoline stations is selected and their mean cost for regular …
  3. Statisics

    I need help on this question i am confused. I don't think the answers i got are right The library checks out an average of 320 books per day, with a standard deviation of 75 books. Suppose a simple random sample of 30 days is selected …
  4. Stats 330- HELP

    I need some help on this question it has two parts but i can't figure it out. Can someone help me. The NDSU library checks out an average of 320 books per day, with a standard deviation of 75 books. Suppose a simple random sample of …
  5. gre math prob of a sample

    sample standard deviation = 3 sample mean = 68 n=30 what is the probability that one student selected at random from the sample will have a height within one sample standard deviation of the sample mean?
  6. statistics

    In a certain region, the mean annual salary for plumbers is $51,000. Let x be a random variable that represents a plumber's salary. Assume the standard deviation is $1300. If a random sample of 100 plumbers is selected, what is the …
  7. stat.

    The average age of a vehicle registered in the United States is 8 years, or 96 months. Assume the standard deviation is 16 months. If a random sample of a group of 48 vehicles is selected find the probability that the mean of the group’s …
  8. statistics

    A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. 2. Identify the population …
  9. statistics

    A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. The population mean …
  10. Statistics

    Daily water intake (including water used in drinks such as coffee, tea and juice) for Canadian adults follows a normal distribution with mean 1.86 litres and standard deviation 0.29 litres. (a) Can you calculate the probability that …

More Similar Questions