Better barley Does drying barley seeds in a kiln increase the yield of barley? A famous experiment by William S. Gosset (who discovered the t distributions) investigated this question. Eleven pairs of adjacent plots were marked out in a large field. For each pair, regular barley seeds were planted in one plot and kiln-dried seeds were planted in the other. The following table displays the data on yield (lb/acre).

(a) How can the Random condition be satisfied in this study?

(b) Perform an appropriate test to help answer the research question. Assume that the Random condition is met. What conclusion would you draw?

Short Answer

Expert verified

a). In each pair of adjacent plots, you randomly allocate one of the plots to be planted with regular barley seeds, while the adjacent plot will then be planted with kiln-dried seeds.

b). There is not sufficient evidence to support the claim.

Step by step solution

01

Part (a) Step 1: Given Information

02

Part (a) Step 2: Explanation

Random sampling provides us with non-aligned data from the population. When samples are collected in an erroneous manner, the data is prone to intolerance.

You will randomly assign one plot to be planted with conventional barley seeds, while the next plot will be planted with kiln-dried seeds in each pair of adjacent plots.

03

Part (b) Step 1: Given Information

04

Part (b) Step 2: Explanation

Determine the difference between "Kiln" and "Regular" for each pair.

05

Part (b) Step 3: Explanation

The mean is the sum of all values divided by the number of values:

x¯=106-20++127+2411

33.7273

nis the number of values in the data set.

The variance is the sum of squared deviations from the mean divided by n-1:

localid="1650366695337" s2=(106-33.7273)2+.+(24-33.7273)211-1

3980.5620

The standard deviation is the square root of the variance:

localid="1650366712856" s=3980.5620

66.1711

06

Part (b) Step 4: Explanation

Determine the hypotheses:

H0:μ=0

Ha:μ>0

Determine the value of the test statistic:

localid="1650366606373" t=x¯-μ0s/n

=33.7273-066.1711/11

=1.690

The P-value is the chance of getting the test statistic's result, or a number that is more severe. The P-value is the number (or interval) in Table B's column title that corresponds to the t-value in row localid="1650366573990" n-1=11-1

=10:

0.05<P<0.10

The null hypothesis is rejected if the P-value is less than the significance level.

P>0.05=5%Fail to rejectH0

There is not sufficient evidence to support the claim.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Study more! A student group claims that first-year students at a university study 2.5hours per night during the school week. A skeptic suspects that they study less than that on average. He takes a random sample of 30first-year students and finds that x=137minutes and sx=45minutes. A graph of the data shows no outliers but some skewness. Carry out an appropriate significance test at the 5%significance level. What conclusion do you draw?

We hear that listening to Mozart improves students’ performance on tests. Maybe pleasant odors have a similar effect. To test this idea, 21subjects worked two different but roughly equivalent paper-and-pencil mazes while wearing a mask. The mask was either unscented or carried a floral scent. Each subject used both masks, in a random order. The table below gives the subjects’ times with both masks.

For the job satisfaction study described in Section 9.1, the hypotheses are

H0:μ=0Ha:μisnotequalto0

where μis the mean difference in job satisfaction scores (self-paced machine-paced) in the population of assembly-line workers at the company. Data from a random sample of 18workers gave x=17and sx=60

Calculate the test statistic. Show your work.

Radon detectors Radon is a colorless, odorless gas that is naturally released by rocks and soils and may concentrate in tightly closed houses. Because radon is slightly radioactive, there is some concern that it may be a health hazard. Radon detectors are sold to homeowners worried about this risk, but the detectors may be inaccurate. University researchers placed a random sample of 11detectors in a chamber where they were exposed to 105picocuries per liter of radon over 3days. A graph of the radon readings from the 11detectors shows no strong skewness or outliers. The Minitab output below shows the results of a one-sample t interval. Is there significant evidence at the 10%level that the mean reading μdiffers from the true value 105? Give appropriate evidence to support your answer.

The P-value for a two-sided test of the null hypothesis H0:μ=10is 0.06

(a) Does the95%confidence interval forMinclude 10? Why or why not?

(b) Does the 90%confidence interval forMinclude 10? Why or why not

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free