A proposed null hypothesis states that there is no difference between the mean weights of the population of two neighboring districts. The sample mean difference is 12 kilograms, and the standard deviation of the distribution of the difference between sample means is 9 kilograms.Which statement is true?
A. The null hypothesis must be accepted if we choose the 68% confidence level.
B. The null hypothesis must be accepted if we choose the 95% confidence level.
C. The null hypothesis must be rejected if we choose the 99.7 % confidence level.
D. The null hypothesis must be rejected if we choose the 100% confidence level.
E. The null hypothesis must be rejected if we choose the 95% confidence level.
(This is all the information that is given)
Using Empirical rule,
68% CI for true mean difference: (mean-SD,mean+SD)=(12-9,12+9)=(3, 21).
95% CI for true mean difference: (mean-2*SD,mean+2*SD)=(12-2*9,12+2*9)=(-6, 30).
Since 95% CI for true mean difference contains zero hence The null hypothesis must be accepted if we choose the 95% confidence level.
Option: B. The null hypothesis must be accepted if we choose the 95% confidence level.
A proposed null hypothesis states that there is no difference between the mean weights of the...
A teacher wants to compare scores on a geology exam for two classes. The difference between the sample means is 21.4. If the standard deviation of the distribution of the difference between sample means is 16.66, and she is testing the hypothesis at the 68% confidence level, which statement is true? A. The difference between the two means is significant, so the null hypothesis must be accepted. B. The difference between the two means is not significant, so the alternative...
Include null and alternate hypothesis, a p-value, and a conclusion PRIVATE about the null hypothesis A study was conducted to estimate the difference in the mean salaries of elementary school teachers from two neighboring states. A sample of 10 teachers from the Indiana had a mean salary of $28,900 with a standard deviation of $2300. A sample of 14 teachers from Michigan had a mean salary of $30,300 with a standard deviation of $2100. Determine a 95% confidence interval for...
A 90% confidence interval for the difference between the means of two independent populations with unknown population standard deviations is found to be (-0.2, 5.4). Which of the following statements is/are correct? CHECK ALL THAT APPLY. A. The null hypothesis that the two population means are equal is not rejected at the 10% significance level using a two-sided paired tt-test. B. The null hypothesis that the two population means are equal is rejected at the 10% significance level using a...
The null hypothesis states there will be no difference in scores on the ADS between face-to-face counseling and video conference counseling. The results are t(38) = 0.258, p = .798. Group Statistics Group N Mean Std. Deviation Std. Error Mean ADS face to face video 20 20 9.2500 9.0000 3.14350 2.97357 .70291 .66491 Independent Samples Test Levene’s Test for Equality of variance t-test for Equality of Means F Sig. t df Sig. (2-tailed) Mean Difference Std. Error Difference 95% Confidence...
Q1 If a null hypothesis is rejected at the 0.10 level of significance, it.... a)must be rejected at the 0.05 level b) may be rejected at the 0.05 level c) will not be rejected at the 0.05 level d) must be rejected at the 0.025 level Q2) the precision of confidence intervals is related to... a) the sample size and the confidence level b) the mean of the population and the confidence level c) the mean of the sample and...
In order to compare the means of two populations, independent random samples of 400 observations are selected from each population, with the results found in the table to the right. Complete parts a through e below. Sample 1 overbar x = 5,305 s1= 154 Sample 2 overbar x = 5,266 s2 = 199 a. Use a 95% confidence interval to estimate the difference between the population means (mu 1 - mu 2). Interpret the confidence interval. The confidence interval is...
1. Please test hypothesis for a mean or for a proportion. Please state null and alternative hypothesis Hypothesized mean = 125, sample mean = 135, standard deviation = 15; n= 500, confidence level = 95% 2. Test Hypotheses of population percent = 33%， sample percent = 31%，n= 120， confidence level = 99%
In hypothesis testing for a population mean, the term "significant difference" implies a: A) difference between the sample mean and the hypothesized population mean that leads to the rejection of the null hypothesis. B) difference between the test statistic and the critical region. C) difference between the one-sided test and the two-sided test. D) difference between the sample standard deviation and the population standard deviation.
If the null hypothesis is that the population mean is equal to 150 and a sample mean of 113 gave significant support against the null hypothesis, which of the following sample means would be certain to give support against the null hypothesis. a) 114 b.) 122 c.) 264 d.) 112 _____12) If the p-value is less than the significance level, you would . a.) reject the null hypothesis b.) accept the...
Question 1 In a chi -square test of independence , the null hypothesis states that-----------. a. the two variables of interest are related in the population. b. the column frequencies equal the row frequencies c. the sum of the and the column frequencies equal the total frequency d. the two variables of interest are unrelated in the population Question 2 A survey asked people whether they identified as a morning person, night person, or had no preference. a. 270 replied...