9. Suppose that systolic blood pressures of a certain population are normally distributed with a mean of 120, a standard deviation of 4, and a sample size 28 is taken from this population, what is the probability that a single sample will have a mean blood pressure of less than 125?
9. Suppose that systolic blood pressures of a certain population are normally distributed with a mean of 120, a standard deviation of 4, and a sample size 28 is taken from this population, what is the probability that a single sample will have a mean blood pressure of less than 125?
Chapter8: Sequences, Series,and Probability
Section8.7: Probability
Problem 11ECP: A manufacturer has determined that a machine averages one faulty unit for every 500 it produces....
Related questions
Question
Bs 9 an 10
Transcribed Image Text:B, Read and answer the following problems with random samples taken from the normal population.
Show all the necessary solutions.
1. Theaverage onlineteacher's salaryperhour is P380.00withastandarddeviationof P51.00. Fors
sample of 75 online teachers, what is the probability that the sample mean is greater thanP400.00
2. The national average percentage score of Grade 6 in National Achievement Test (NAT) recenul
for Math subject is 36.66 with a standard deviation of 3.57. Ifa random sample of 200 scores w
selected, what is the probability that the sample average percentage score is higher than 45
3. The number of hours spent playing mobile legends a day by teenagers has a mean of 8 hour
with a standard deviation of 3.5 hours. Find the probability that if you select 50 random
teenagers, the mean number of hours a day spent playing games is between 5 and 7.5 hours
4. Kyle has a collection of more than 300 songs in his phone that has a mean duration of 2.75
minutes and a standard deviation of 0.6 minutes. Suppose that every week he makes a
playlist by taking random sample of 36 of these songs, calculate the sample mean duration
of the songs and the standard error of the sampling distribution of the sample means.
5. On the average, basketball players drink 2.3 liters of water with a standard deviation
of 0.9 liter during a game. If the team manager asks his assistant to bring 45 liters
of water for 15 players, what is the probability that they will run out of water?
6. Suppose that students who finished JHS in a public school get an average of 5.6 hours of sleep
each night with a standard deviation of 1.7 hours. What is the probability that a random selected
group of 35 public school students get more than 6 hours of sleep, on the average each night?
7. The average life of a smartphone is 7 years with a standard deviation of 1 year. Assuming
that the lives of these phones follow approximately a normal distribution, find the probability
that the mean life of a random sample of 9 smartphones fall between 6.4 and 7.2 years.
8. Given a normal random variable X with a mean of 20, a variance of 9, and a random sample of n
takenfrom the distribution, whatsamplesize (n)isnecessaryinorderthat P(19.9< X <20.1)=0.95?
ba Je o n ge.dtagoy lmon sdi l.dat s via
9. Suppose that systolic blood pressures of a certain population are normally distributed with a
mean of 120, a standard deviation of 4, and a sample size 28 is taken from this population,
what is the probability that a single sample will have a mean blood pressure of less than 125?
ssda alqmsa ads
10. Study reports that the average person uses 120 liters of water daily. If the standard deviation
is 20 liters, find the probability that the mean of randomly selected sample of 15 people will be
between 120 and 125 liters.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
Recommended textbooks for you
