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: Illustrate the null hypothesis for a correlated t test?

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: 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: 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: 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: 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: 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: (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: 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: 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: 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: 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.