Question

You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...

You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35 bacteria reveals a sample mean of ¯x=64x¯=64 hours with a standard deviation of s=4.8s=4.8 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 90% level of confidence.

What sample size should you gather to achieve a 0.45 hour margin of error? Round your answer up to the nearest whole number.

Homework Answers

Answer #1

Solution :

Given that,

standard deviation =s =   =4.8

Margin of error = E = 0.45

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z0.05 = 1.645

sample size = n = [Z/2* / E] 2

n = ( 1.645 *4.8 /0.45 )2

n =307.8

Sample size = n =308

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35 bacteria reveals a sample mean of ¯x=66x¯=66 hours with a standard deviation of s=4.8s=4.8 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 98% level of confidence. What sample size should you gather to achieve a 0.45 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35 bacteria reveals a sample mean of x ¯ = 74 hours with a standard deviation of s = 4.8 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.65 hours at a 90% level of confidence. What sample size should you gather to achieve a 0.65 hour margin of error?...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of ¯x=78x¯=78 hours with a standard deviation of s=6s=6 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 95% level of confidence. What sample size should you gather to achieve a 0.45 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 25 bacteria reveals a sample mean of ¯x=72x¯=72 hours with a standard deviation of s=5.8s=5.8 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 95% level of confidence. What sample size should you gather to achieve a 0.45 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35 bacteria reveals a sample mean of ¯ x = 76 x¯=76 hours with a standard deviation of s = 5.6 s=5.6 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.65 hours at a 90% level of confidence. What sample size should you gather to achieve a 0.65 hour margin...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of ¯x=78 hours with a standard deviation of s=4 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.7 hours at a 90% level of confidence. What sample size should you gather to achieve a 0.7 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 30 bacteria reveals a sample mean of ¯x=70x¯=70 hours with a standard deviation of s=6.6s=6.6 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.65 hours at a 98% level of confidence. What sample size should you gather to achieve a 0.65 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 30 bacteria reveals a sample mean of ¯x=66x¯=66 hours with a standard deviation of s=6.6s=6.6 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.7 hours at a 99% level of confidence. What sample size should you gather to achieve a 0.7 hour margin of error? Round your answer up to...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample...
You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of ¯x=66x¯=66 hours with a standard deviation of s=6.8s=6.8 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.75 hours at a 95% level of confidence. What sample size should you gather to achieve a 0.75 hour margin of error? Round your answer up to...
A researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40...
A researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 40 bacteria reveals a sample mean of ¯x=74x¯=74 hours with a standard deviation of s=6s=6 hours. He would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.6 hours at a 90% level of confidence. What sample size should you gather to achieve a 0.6 hour margin of error? He would need to sample bacteria.