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A retail analytics team at a major e-commerce platform tests whether a redesigned digital advertising campaign (Campaign A) produces a strictly higher click-through rate than the existing campaign (Campaign B). Independent samples: Group 1 (Campaign A), n1=500 users, f1=230 clicked through (p^1=0.4600); Group 2 (Campaign B), n2=500 users, f2=215 clicked through (p^2=0.4300). A right-tailed two-sample proportions z-test at α=0.01 returns pooled proportion p^=0.4450, standard error =0.031431, test statistic z=0.9545, p-value =0.1699, critical value zcv=2.5762, and CI99=(−0.050973,0.110973). Select all statements that are TRUE.

A marine biologist investigates whether the mean body weight of adult sea urchins in a newly established marine reserve has changed from the historical population mean of 24 grams (H0:μ=24, H1:μ≠24). A random sample of n=30 sea urchins yields x¯=25.5 grams and s=3.5 grams. With the population standard deviation unknown, the Stats Kingdom calculator uses a two-tailed t-test at α=0.05, returning t=2.3474, critical values =±2.0452, p-value =0.0259, and df=29. Select all statements that are TRUE.

In 2001, Argentina experienced a financial crisis.  In response, the Argentine government froze access to bank accounts for a year. Argentineans had no access to their money.​Many banks subsequently went under, costing Argentine citizens their bank-based savings. The event was not a complete surprise. The Argentine government had a history of freezing bank accounts, such as during financial crises in 1982 and 1989.​What affect, if any, do you think these freezes will have on the ability of Argentine banks to perform their financial intermediation functions in the future? Be sure to explain your answer.

While driving on the highway, a truck in front of you kicks up a stone that shatters your windshield, forcing you to replace it. A friend says, “At least it’s good for the economy—the windshield shop will earn money, and their employees will benefit. The net effect is a better overall economy.”  Using the Economic Way of Thinking, evaluate your friend’s claim that the broken windshield benefits the economy overall.  Be sure to explain your reasoning.

When inflation causes relative-price variability, consumer decisions

A comet moves in the Sun’s gravitational field along an elliptical path. What happens to its angular momentum as it moves from point X to point Y?

A toy car of mass 6 kg experiences net force F = −3t (SI units). At t = 0, v = +4 m/s and x = +8 m. The car will come instantaneously to rest at time t equal to

A child of mass 20 kg running at 4.0 m/s jumps onto a stationary sled of mass 5.0 kg on frictionless ice. The speed at which the child and sled begin to slide is most nearly

A newly discovered planet has twice the radius and five times the mass of Earth. If Earth’s surface gravity is g, the planet’s surface gravity is

A stone falls from rest from the top of a building. Which graph best represents the stone’s angular momentum L about a point P as a function of time?