The modulus of elasticity of structural components was measured one minute after loading. The same samples...

The modulus of elasticity of structural components was measured one minute after loading. The same samples were tested again after 4 weeks. The following table shows the values of modulus of elasticity in both cases.Conduct an appropriate hypothesis test for the true average difference between the modulus in the two cases. Clearly state your conclusions.. Data is also available

Sample Number	After 1 minute	After 4 weeks
1	10490	9110
2	16620	13250
3	17300	14720
4	15480	12740
5	12970	10120
6	17260	14570
7	13400	11220
8	13900	11100
9	13630	11420
10	13260	10910
11	14370	12110
12	11700	8620
13	15470	12590
14	17840	15090
15	14070	10550
16	14760	12230

Solutions

Expert Solution

In this case we cannot make use of independent samples t-test, rather we will make use of a paired t-test.

Let the subscript 1 denote the reading after 1 minute, and 2 denote the readings after 4 weeks.

The hypotheses are:

H0: 1 = 2

Ha: 1 > 2

The results as obtained from excel are shown below:

As seen in the result above, the p-value (shown in green) for this one tailed hypothesis test is much less than the significance level of 0.05

Thus the result is significant, and we have to reject the null hypothesis.

Thus there is significant evidence that modulus of elasticity has decreased for the group in which reading is taken after 4 weeks.

orchestra answered 2 years ago

Next > < Previous

Related Solutions

Measured Amounts of arsenic from independent samples of the same size of brown rice can be...

Measured Amounts of arsenic from independent samples of the same size of brown rice can be found in Arsenic in rice. All measurements are in micrograms per serving and the data is from the food and drug administration. each sample appears to be from a population having a normal distribution. use a 0.05 significance to test the claim that the mean amount of arsenic in rice is the same in california, arkansas, and texas. CA AR TX 1.5 4.8 5.6...

Cholesterol (mg/dL) was measured in the same patients before and after taking drug D. Do a...

Cholesterol (mg/dL) was measured in the same patients before and after taking drug D. Do a Wilcoxon signed-rank test for paired samples: state the null and (non-directional) alternative hypotheses, calculate (or bound) the p- value, and clearly state your conclusion for significance level ? = 0.05. The appropriate table is at the end of the quiz. Before. After 200 250 190 245 180 175 190 188 180 500 200 260 190 260 190 230 a) Why would you do...

You have placed a copper pot with water to heat on the stove. After one minute...

You have placed a copper pot with water to heat on the stove. After one minute you place your finger in the water and you are okay. When you touch the pot your finger gets burned. Upload a drawing of a molecular view of what the copper atoms and water molecules look like at the beginning of heating the pot and after the pot has been heated for 15 mins.

In one batch of nickel (Ni)-plated cast iron components, you observed that there were minute pores...

In one batch of nickel (Ni)-plated cast iron components, you observed that there were minute pores in the Ni surface coating growing down to the cast iron surface.Should you allow this batch of nickel (Ni)-plated cast iron components be used for a water treatment application? Will the component be susceptible to corrosion and what form of corrosion could occur?

(1 point) Sheila's measured glucose level one hour after a sugary drink varies according to the...

(1 point) Sheila's measured glucose level one hour after a sugary drink varies according to the Normal distribution with μμ = 130 mg/dl and σσ = 20 mg/dl. What is the level L such that there is probability only 0.1 that the mean glucose level of 4 test results falls above L? L=

Sheila's measured glucose level one hour after a sugary drink varies according to the Normal distribution...

Sheila's measured glucose level one hour after a sugary drink varies according to the Normal distribution with μμ = 120 mg/dl and σσ = 20 mg/dl. What is the level L such that there is probability only 0.15 that the mean glucose level of 4 test results falls above L?

Shelia's measured glucose level one hour after a sugary drink varies according to the Normal distribution...

Shelia's measured glucose level one hour after a sugary drink varies according to the Normal distribution with µ = 118 mg/dl and s = 10 mg/dl. What is the level L (±0.1) such that there is probability only 0.01 that the mean glucose level of 4 test results falls above L?

Shelia's measured glucose level one hour after a sugary drink varies according to the normal distribution...

Shelia's measured glucose level one hour after a sugary drink varies according to the normal distribution with ?=132μ=132 mg/dl and ?=10.5σ=10.5 mg/dl. What is the level L such that there is probability only 0.05 that the mean glucose level of 4 test results falls above ?L? Give your answer precise to one decimal place.

Assume that the 3 players are dealt (one after another) 7 cards each from the same...

Assume that the 3 players are dealt (one after another) 7 cards each from the same well-shuffled deck of 52 cards. What is the probability that at least one of the players will get four spades? (any order) What is the probability that none of them gets four spades?

Mike’s total utility from doing the same activity over and over is 50 utils after one...

Mike’s total utility from doing the same activity over and over is 50 utils after one repetition, 90 utils after two repetitions, 70 utils after three repetitions, 20 utils after four repetitions, -50 utils after five repetitions, and -200 utils after six repetitions. Write down his marginal utility for each repetition. Once Mike’s total utility begins to decrease, does each additional repetition of the activity hurt more than the previous one or less than the previous one?

Subjects