Question

URGENTTT

1) In a study investigating the effect of car speed on accident severity, 5,000 reports of fatal automobile accidents were examined, and the vehicle speed at impact was recorded for each one. For these 5,000 accidents, the average speed was 46 mph and the standard deviation was 12 mph. A histogram revealed that the vehicle speed at impact distribution was approximately normal. (Use the Empirical Rule.)

(a) Approximately what percentage of vehicle speeds were between 34 and 58 mph?

(b) Approximately what percentage of vehicle speeds exceeded 58 mph? (Round your answer to the nearest whole number.)

2) A number of initiatives on the topic of legalized gambling have appeared on state ballots. A political candidate has decided to support legalization of casino gambling if he is convinced that more than two-thirds of U.S. adults approve of casino gambling. Suppose that 1527 adults selected at random from households with telephones were asked whether they approved of casino gambling. The number in the sample who approved was 1032. Does the sample provide convincing evidence that more than two-thirds of U.S. adults approve? (Use  α = 0.05.)

Round your test statistic to two decimal places and your P-value to four decimal places.)

z=

P-value=

Answer 1

Solution (1)

Above graph shows empirical relationship.

Q (2) solution