REVIEWER FOR STATS

• HYPOTHESES TESTING - Statistical method used in making decisions using experimental data.
• HYPOTHESIS - A proposed explanation, assertion, or assumption about a population parameter or about the distribution of a random variable.
• Not equal sign (≠) - symbols/ describes an alternative hypothesis using a two-tailed test.
• Type I error committed - when we reject null hypothesis, its true.
• Type II error committed - When we accept the null hypothesis and reject the alternative hypothesis.
• If the computed z-value is 2.015 and the critical value is 1.833, which of the following statements could be true?

  It lied in the rejection region, Ho must be rejected
• PARAMETER - Numerical measure describes the certain characteristics of a population.
• POPULATION - Denotes the true value that would be obtained if a census rather than a sample was undertaken.
• A study claims that the mean survival time for a certain cancer patient treated immediately with chemo and radiation is 24 months. What is the parameter ?

  The mean survival for a certain cancer patient treated immediately with chemotherapy and radiation is 24 months.
• In formulatingthe alternative hypothesis, what mathematical symbol is applicable to use in the statement, The average score of BSIE in statistical analysis I is 80.”?

  not equal sign 80(≠80)
• Which pf the following steps is not included in formulating hypothesis ?

  Use the data about sample then compute the test statist.
• A scientist invented a substance that increases the life of an automobile battery. If the mean lifetime of the battery is 24 months, then what are his hypothesis ?

  =24 and >24
• CRITICAL VALUE - Value that separates a rejection region from an acceptance region.
• In the two-tailed test, the rejection region lies on _____ of the normal distribution?

  Both tail
• Given the normal curve at the right, what is the rejection region?

  Left of 1.96

  Right of 1.96
• Sketch of the normal curve if z_>1.645?

  graph
• TEST STATISTICS - Refers to the value calculated from sample data which in needed in deciding whether the null hypothesis is reje or not.
• Z-TEST - test statistics will be used if the sample size is above 30.
• Z-TEST - Test statis tic can be used when the population standard deviation is known
• When findinf the z-computed value, which formula should be used for hypothesis testing ?

  : z = x−μ /σ√n
• When should you use the t-test?

  •When you are testing for a population mean

  •When the sample standard deviation is given
• When we failed to reject the null hypothesis, which of the following statement is true?

  There is not enough evide to reject the claim.
• What does it mean when the null hypothesis is rejected ?

  There is sufficient evidence to disprove the null hypothesis.
• What should you do if the computed z-value lies in the critical region?

  Reject the null hypothesis
• What is the last step in the hypothesis testing procedure ?

  Draw a conclusion