Question

The sample mean weights for two varieties of lettuce grown for 16 days in a controlled...

The sample mean weights for two varieties of lettuce grown for 16 days in a controlled environment are 3.259 and 1.413 and the corresponding sample standard deviations are .400 and .220. If the sample sizes for the two varieties are 9 and 6 respectively, calculate the pooled sample standard deviation:

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Solution

Given ,

  =3.259 , = 1.413

s1 = 0.400 , s2 = 0.220

n1 = 9 , n2 = 6

Let denotes the pooled variance and denotes the pooled standard deviation.

=

=   

=  

=  0.34216505239

Answer : The pooled sample standard deviation: 0.34216505239

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Sample mean chlorophyll concentrations for the four Jerusalem artichoke varieties were 0.29, 0.25, 0.40, and 0.32,...
Sample mean chlorophyll concentrations for the four Jerusalem artichoke varieties were 0.29, 0.25, 0.40, and 0.32, with corresponding sample sizes of 5, 5, 4, and 6, respectively. In addition, MSE = 0.0130. Calculate the 95% T-K intervals. (Use Table 7 in Appendix A. Round all answers to four decimal places.) μ1-μ2: ( , ) μ1-μ3: ( , ) μ1-μ4: ( , ) μ2-μ3: ( , ) μ2-μ4: ( , ) μ3-μ4: ( , )
A random sample of 16 winter days in Denver gave a sample mean pollution index of...
A random sample of 16 winter days in Denver gave a sample mean pollution index of 43 with a standard deviation of 16. For Englewood (a suburb of Denver), a random sample of 17 winter days gave a sample mean pollution index of 51 with a standard deviation of 13. Do these data indicate that the mean population pollution index of Englewood is different (either way) from that of Denver in the winter? Use a 1% level of significance. show...
12.16 Calculating the pooled standard deviation. An experiment was run to compare three groups. The sample...
12.16 Calculating the pooled standard deviation. An experiment was run to compare three groups. The sample sizes were 28, 33, and 102, and the corresponding estimated standard deviations were 2.7, 2.6, and 4.8. (a) Is it reasonable to use the assumption of equal standard deviations when we analyze these data? Give a reason for your answer. (b) Give the values of the variances for the three groups. (c) Find the pooled variance. (d) What is the value of the pooled...
An agricultural economist wants to know if the average number of plants grown differs for two...
An agricultural economist wants to know if the average number of plants grown differs for two different fertilizers, which we will call Fertilizer 1 and Fertilizer 2. He samples 45 plants from a field sprayed with Fertilizer 1 and 45 plants from a field sprayed with Fertilizer 2. The sample standard deviations are 4 and 1, respectively. What test should be conducted and with what degrees of freedom? (For the degrees of freedom, assume the agricultural economist does not have...
Suppose x has a normal distribution with mean μ = 16 and standard deviation σ =...
Suppose x has a normal distribution with mean μ = 16 and standard deviation σ = 11. Describe the distribution of x values for sample size n = 4. (Round σx to two decimal places.) μx = σx = Describe the distribution of x values for sample size n = 16. (Round σx to two decimal places.) μx = σx = Describe the distribution of x values for sample size n = 100. (Round σx to two decimal places.) μx...
Suppose the mean and standard deviation for weights of NFL guards since 1970 is 310 lbs...
Suppose the mean and standard deviation for weights of NFL guards since 1970 is 310 lbs and 20 lbs respectively; for NFL quarterbacks since 1970 they are 220 lbs and 15 lbs, respectively. Weights within each position are bell shaped. Suppose random samples of 40 guards and 50 quarterbacks are measured and the sampling distribution is the difference in sample means, found by subtracting the quarterbacks from the guards (guards - quarterbacks).
If the population mean is 1000 For n = 9 ,16 , 25 , 49, 100,...
If the population mean is 1000 For n = 9 ,16 , 25 , 49, 100, 400 , 900, 1600, 2500, 4000, 10000 Compute the sample mean for each value If the population standard deviation is 100 What is the sample means standard deviation For n = 9 ,16 , 25 , 49, 100, 400 , 900, 1600, 2500, 4000, 10000 How does the variance change as we increase the sample size?
Suppose the lengths of human pregnancies are normally distributed with mean= 266days and standard deviations =16...
Suppose the lengths of human pregnancies are normally distributed with mean= 266days and standard deviations =16 days. Complete parts ​(a) and​ (b)below. (a) The figure to the right represents the normal curve with mean is  266 days and standard deviation 16days. The area to the left of X= 245 is 0.0947. Provide two interpretations of this area. ​(b) The figure to the right represents the normal curve with mean is 266 days and the standard deviation is 16days. The area between...
A random sample of n1 = 14 winter days in Denver gave a sample mean pollution...
A random sample of n1 = 14 winter days in Denver gave a sample mean pollution index x1 = 43. Previous studies show that σ1 = 21. For Englewood (a suburb of Denver), a random sample of n2 = 12 winter days gave a sample mean pollution index of x2 = 37. Previous studies show that σ2 = 17. Assume the pollution index is normally distributed in both Englewood and Denver. (a) Do these data indicate that the mean population...
A random sample of 49 measurements from one population had a sample mean of 16, with...
A random sample of 49 measurements from one population had a sample mean of 16, with sample standard deviation 5. An independent random sample of 64 measurements from a second population had a sample mean of 19, with sample standard deviation 6. Test the claim that the population means are different. Use level of significance 0.01. (a) What distribution does the sample test statistic follow? Explain.(c) Compute x1 − x2. x1 − x2 = Compute the corresponding sample distribution value....
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT