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Excel worksheets showing solutions to problem similar to Problem Quiz problems can be found under Student Resources.

A learning-center coordinator studies whether weekly tutoring hours x predict module assessment score y. The data were entered in the order students completed the course, not in sorted x-value order. Use the following data to compute the simple linear regression equation and then predict y when x = 5.3. x              y4.8          38.41.2          17.67.2          49.63.6          29.86.0          42.02.4          21.2 Enter the slope [slope]____, intercept [intercept]____, and predicted ŷ for x = 5.3 [y-hat]____.(round each answer to 2 decimals)

Suppose a researcher claims: μ₁ ≥ μ₂ The hypotheses are set up as: H₀: μ₁ ≥ μ₂; H₁: μ₁ < μ₂ If the test decision is reject H₀, then the original claim is supported.

A two-proportion test has H₁: p₁ > p₂ and α = 0.07. Enter the left [left]_____ and right [right]_____critical values. If there is no critical value enter “na”. (round to 3 decimals)

A two-sample test has H₁: p₁ ≠ p₂ and alpha = 0.04 Which Excel formula gives the correct right critical value?

A variance test has: H1:σ2>144 α=0.04 degrees of freedom df=22 Using Excel’s right-tail chi-square function, which formula gives the correct critical value?

A random sample of 420 customers finds that 36% prefer self-checkout. A 95% confidence interval will be constructed for the true population proportion. What is the margin of error E?

The time required to complete a software update is normally distributed with mean μ = 38 minutes and standard deviation σ = 5 minutes. What is the probability that a randomly selected update takes more than 45 minutes?

An agronomist studies yield using 4 seed varieties, Factor A, and 3 irrigation levels, Factor B. There are 3 replicated plots in each variety/irrigation combination. Excel gives: Interaction p-value = 0.0524Factor A p-value = 0.0007Factor B p-value = 0.0041 Using the instructions above, and assuming as alpha = 0.05, enter yes or no to the following questions: Is the interaction significant? [intsig]_____ Are all Factor A’s different from each other? [F1sig]_____ Is as least one Factor B different from at least one other Factor B? [F2sig]____

An insurance auditor claims that the variance in monthly claim amounts is not equal to 400. Complete the written hypothesis shown below. Use only these possible signs: =, =,  [H0H1]____ (enter H0 or H1): mu [sign]______ (enter the correct sign) [value]_____ (enter the value)