Explain the difference between a left-tailed, two-tailed, and right-tailed test. When would we choose a two-tailed test?

How can we tell the direction of the test by looking at a pair of hypothesis?

How can we tell which direction (or no direction) to make the hypothesis by looking at the problem statement (research question)?

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In every hypothesis testing problem, there is a pair of competing statistical hypotheses: the null hypothesis and the alternative hypothesis. The Null hypothesis, denoted by H0, is typically a clear statement of equality: the unknown population parameter θ is equal to some specific constant value θ0 (the hypothesized value of population parameter θ).

In symbolic form this hypothesis is written as H0 : θ = θ0

The null hypothesis is also called the no-difference hypothesis, because it states that there is no difference between θ and θ0

The alternative hypothesis, denoted by H1, is an assumption about θ that differs from H0.

If the alternative hypothesis is left directional, in other words, if we test the null hypothesis H0 : θ = θ0¬ against the alternative hypothesis
H1 : θ < θ0¬¬, then this hypothesis test is ...

Solution Summary

This response differentiates between the left-tailed, two-tailed, and right-tailed test. It also explains how to tell the direction of a test by looking at the hypotheses.

I've been trying to understand the differences between one tailed and two tailed testing, t and z testingand p value. I think I understood #5 but need some help with #18, 23 and 44.
18. The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the

You will be asked to determine the correct decision (Reject Ho or Fail to Reject Ho) for each of the following tests of hypotheses.
1. A hypothesis test at the 0.025 level of significance with a p-value for the sample of 0.0075.
2. A hypothesis test at the 0.01 level of significance with a p-value for the sample of 0.012

Explain the difference between a left tail, two-tailed,and right tailed text. When would we choose a two tailed test? How can we tell the direction by looking at a pair of hypothesis? How can we tell which direction (or no direction) to make the hypothesis by looking at the problem statement (research question)?

Introduction to Hypothesis Testing
State the claim mathematically. Then write the null and alternative hypothesis. Determine whether the hypothesis test is left-tailed,right-tailed, or two-tailed.
a. A research hospital claims that more than 3.7% of the population suffers from high blood pressure. Use p, the represent

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What is a one-tailed t

Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z value used to test the null hypothesis.
=0.05 for a left-tailed test.
-1.645
1.96
1.645
-1.96
Use the given information to find the P-value.
The test statisti

The 65 students in a class at the University of Soda were given blinded evaluations of pairs of cola drinks. For the 65 comparisons of Coke and Pepsi making up the sample results, Pepsi was preferred 29 times.
a. Is the above information sufficient for you to be completely certain that more than 50% of all students at that u

A researcher is looking at the relationship between home-schooling and achievement. She is hypothesizing that the home-schooled children will score higher than non home-schooled children on a standardized achievement test.
a. What is the null hypothesis?
b. What is the alternative hypothesis? (Remember that every possibility

Suppose that we observe a random sample size n from a normally distributed population. If we are able to reject H0:µ = µ in favor of a two-tailed alternative hypothesis at the 10% significant level, is it true that we can definitely reject H0 in favor of the appropriate one-tailed alternative at the 5% significant level? Why o