Deviation Of Height

So, we should reject the null hypothesis H0. At a 0.05 level of significance level, we conclude that there is a significant difference between the average height for females and the average height for the males.

2) Compute the standard deviation for each of the four samples. Does the assumption of .21 for the population standard deviation appear reasonable?

2. In order to determine the average amount spent in November on Amazon.com a random sample of 144 Amazon accounts were selected. The sample mean amount spent in November was $250 with a standard deviation of $25. Assuming that the population standard deviation is unknown, what is a 95% confidence interval for the population mean amount spent on Amazon.com in November?

(21) You took a sample of size 21 from a normal distribution with a known standard deviation, . In order to find a 90% confidence interval for the mean, You need to find.

The mean for the column “mean” is 3.56. It is very close to the parameter of interest but is not equal to it. You can calculate a confidence interval for the mean of the mean column, but a specific confidence interval would need to be provided. In that case, the confidence interval would be centered on 3.56, not 3.5.

A business wants to estimate the true mean annual income of its customers.  It randomly samples 220 of its customers.  The mean annual income was $61,400 with a standard deviation of $2,200.  Find a 95% confidence interval for the true mean annual income of the business’ customers.

Body weight expressed as a percentage of ideal in an SRS of n = 9 girls selected at random are as follows {114, 100, 104, 94, 114, 105, 103, 105, 96}. Calculate a 95% confidence interval for the population mean µ.

The null hypothesis is rejected since the p-value is below the significance level of 0.05.

When you perform a test of hypothesis, you must always use the 4-step approach: i. S1:the “Null” and “Alternate” hypotheses, ii. S2: calculate value of the test statistic, iii. S3: the level of significance and the critical value of the statistic, iv. S4: your decision rule and the conclusion reached in not rejecting or rejecting the null hypothesis. When asked to calculate p–value, S5, relate the p-value to the level of significance in reaching your conclusion.

This lab could have contained errors. The errors could have happened when performing the lab. Some of the possible errors in this lab are:

Conclusion : Fails to reject the null hypothesis. The sample does not provide enough evidence to support the claim that mean is significantly different from 12 .

The scientific question of the project was, Does the size of a tire affect the bike’s speed? The hypothesis was , If the smaller tires were used, then the bike would go faster. The important procedures were: Make sure all equipment is ready. Test the standard wheel of 1 rotation or pedal a second to ride to the finish line. Test smaller and bigger wheels. Record data and have at least 3 trials. Record the data on a piece of paper and compare results to your hypothesis. The Independent variable is the size of the wheel on the bike. The Dependent variable is the standard wheel or tire on the bike. The control group was the bike’s speed and the standard wheel or tire. The Experimental group is the other tires or wheels being tested on the bike. The control variables were the rate of pedaling , the same bike model was used, and the same distance for

The 95% confidence interval for the population mean is 66,438 to 80,241. This means that there is a 95% confidence that this interval has the population mean.

A type I error occurs when incorrectly rejecting the null hypothesis. The probability of a type I error equals alpha (the level of significance). There is always a possibility of type I error, using multiple t test increase the probability of committing a type I error. Type I errors occur for each t- test, the probability of making type I error from each test will increase. ANOVA is a way to test multiple null hypothesis at the same time. ANOVA test reduces the probability of committing a type I error because the F test is only used once. One test reduces the room for type I errors.

b) The same article reported the mean size was more than 2100 square feet? Can we conclude that the mean size of homes sold in the Gulshan area is more than 2100 square feet? Use the 0.05 significance level. What is the