A researcher knew that before cell phones, a person made on average 2.8 phone calls per day. She believes that the number of phone calls made per day today is higher. A random sample of 30 people had a sample mean x = 3.1. The standard deviation for the population found by a previous study is o = 0.8. Test the hypothesis that the population mean is 2.8 against the .. alternative hypothesis that the population mean is greater than 2.8,at the 0.05 level of significance.

Q: True or False  In a hypothesis testing, if the p-value is less than the significance level a, we do…

A: Significance level: It is the proability of rejecting the null hypothesis when it is true. p-value:…

Q: Illustrate the null hypothesis for a correlated t test?

A:

Q: It is the measure of association between two random variables obtained as the expected value of the…

A:

Q: What are important features of hypothesis testing?

A: Hypothesis testing is a crucial procedure to perform when it is expected to make inferences about a…

Q: 4) Among the statements below, which one is not correct in the statistical inference for one…

A: The following statements are given in the question we have to check which one are incorrect for…

Q: ANOVA calculations and rejection of the null hypothesis

A: First, we need to calculate the treatment total (T) for each treatment group. To do this, we…

Q: What hypothesis test would you use to compare means from two independent study samples, such as…

A: Null and alternative hypotheses: The hypothesis, which is pre assumed as true, tentatively settled…

Q: Test the claim that the proportion of people who own cats is smaller than 60% at the 0.10…

A: We have to test claim.

Q: Why do we test a null hypothesis instead of a research hypothesis

A: A hypothesis, in general, is an assumptions that is yet to be proved with sufficient pieces of…

Q: In order to make decision in hypothesis testing, p-value is frequently used when Select one: O a.…

A: In order to make decision in hypothesis testing, p-value is frequently used when Explanation: The P…

Q: Anita's, a fast-food chain Specializing in hot dogs and garlic fries, keeps track of the proportion…

A:

Q: If you reject the null hypothesis at the 5% significance level, would you reject it at the 7% level?

A: It is given that we reject the null hypothesis at 5% significance level.

Q: It is tested by a statistical test.   a. Null hypothesis b. Alternative hypothesis c. Test statistic…

A: Given that

Q: Why is the phrase “goodness of t” used to describe the type of hypothesis test considered in this…

A: In this section, the test is to check how well the observed frequencies match with the expected…

Q: The critical value for a one-tail hypothesis test when the population standard deviation is known,…

A: Given, sample size n=50 df=n-1=50-1=49  α = 0.05 ( one-tail hypothesis test) Tc=?

Q: When testing any experimental hypothesis, why is it important that the test you use to measure the…

A: Reliability and validity are crucial for trustworthy hypothesis testing because they ensure the…

Q: The purpose of hypothesis testing is to reach a conclusion about a __________ by examining the data…

A: Result Option 2 is correct. i.e The purpose of hypothesis testing is to reach a conclusion about a…

Q: Significance testing is similar to hypothesis testing, except rather than comparing a p-value to a…

A: Given Information: Null Hypothesis H0:μ≤60 Alternative Hypothesis H1:μ>60 The standard deviation…

Q: 7. The acceptance region is the set of values of the test statistic for which we can accept the null…

A: GIVEN DATA, the acceptance region is the values of the test statistics for which we can accept the…

Q: Recognize when to use a hypothesis test?

A: Hypothesis Testing: The statistical hypothesis is a statement made by the researcher on the basis of…

Q: When the null hypothesis is true, the F test statistic is close to When the null hypothesis is…

A: F-statistics are the ratio of two variances that are approximately the same value when the null…

Q: • Employees from Company A and Company B both receive annual bonuses. What information would you…

A: Null and Alternate Hypothesis: H0: μA- μB=100HA:  μA- μB>100     We will need: Sample size A =nA…

Q: If a researcher does not uncover sufficient evidence for a treatment effect in a hypothesis test,…

A: When , p<0.05 we reject the null hypothesis and conclude that there is not sufficient evidence…

Q: A larger treatment effect means the hypothesis test has more power. True or False?

A: Power of the test explains the chance of not happening type II error. It is the correct rejection of…

Q: If you are running a hypothesis test and increase your sample size, what will happen to your Type I…

A: Higher sample makes higher power of test And smaller sample makes small the power of test

Q: Which of the following is the name for the statistical hypothesis that describes no change, or…

A: The objective of the question is to identify the correct term used in statistics that describes a…

Q: You wish to test the following claim (Ha) at a significance level of a = 0.002. H,: 41 - 2 = 0 Ha:…

A: Testing of Hypothesis :  The provided sample means are shown below:  Also, the provided sample…

Q: A one-tailed hypothesis test of the population proportion is used when the alternative hypothesis…

A: Null hypothesis:The null hypothesis defined usually that whether there is no difference in the test…

Q: (b) Compute the value of the test statistic. Round the answer to at least three decimal places.

A: Given Information: Hypothesized value of population mean μ0=720 Sample size n=50 Sample mean x¯=765…

Q: 7 8 6. 7 7 8 Describe this problem in terms of statistical hypothesis testing framework. How would…

A: Null Hypothesis: A hypothesis which is tested for plausible rejection is called the Null Hypothesis…

Q: Null and alternative hypotheses are statements incorporate  a. population parameters.  b. sample…

A: Null hypothesis is the statement about the population.

Q: Classify the hypothesis test as two-tailed, left-tailed, or right-tailed. At one school, the…

A: Form the given information we have, H0 : μ= 20.1  ( population mean is equal to 20.1) Ha : μ <…

Q: A polling company conducted a hypothesis test to see if people are happy with the government, and…

A: Given : A polling company conducted a hypothesis test to see if people are happy with the…

Q: You wish to test the following claim (Ha) at a significance level of a = 0.02. H,: P1 – 42 = 0 Ha:…

A: State the hypotheses. That is, there is no evidence that the first population mean is greater than…

Q: For the data and sample regression equation shown below, do the following. a. Decide, at the 5%…

A: Given information: x 0 9 9 6 5 y 2 6 7 -3 1 y^=-0.427+0.522·x, ∑x=29, ∑x2=223, β1=0.522,…

Q: Statistics is not about getting accurate results. It is about Finding sufficient evidence to prove…

A: Statistics is the science of collecting, organizing, analyzing, and interpreting data in order to…

Q: If the null hypothesis is false, you cannot make which kind of error? Type I Type II

A: Type I error: The type I error occurs when rejecting the null hypothesis when it is true. It is…

Q: The number of degrees of freedom for the two-sample t-test are the same regardless of whether or not…

A: The degrees of freedom of two sample t test different when ‘population variance are equal’ and…

Q: Suppose we want to test whether or not three means are equal. We want to perform this test with a 8%…

A: Given The level of significance is the prob of making type 1 error in the test. So, alpha=8% means…

Q: When a researcher conducts an experiment and fails to find significant results, what should she…

A: According to the provided information, The researcher conducts an experiment and fails to find…

Q: State the null and alternative hypotheses for the statistical test described. (a) Testing to see if…

A: a) The hypothesis for this test can be constructed as: Null hypothesis: H0: pA = pB Alternative…

Q: In hypothesis testing, if the test statistic is negative, this means the sample statistic is larger…

A: We have given the following statement about  hypothesis testing.

Confidence Intervals

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calculated is present here only.