Question

in 1965, the mean price of a new car was $2,650 and the standard deviation was $1,000. In 2011, the mean was $30,500 and the standard deviation was $9,000. If a Ford Mustang cost $2,300 in 1965 and $28,000 in 2011, in which year was it more expensive relative to other cars.

Answer 1

Answer:

Car were more expensive in 2011

Explanation:

Data provided in the question:

Mean price of the car in 1965 = $2,650

Standard deviation, s = $1,000

Mean price of the car in 2011 = $30,500

Standard deviation in 2011, s = $9,000

Cost in 1965 = $2,300

Cost in 2011 = $28,000

Now,

z score = [ X - mean ] ÷ s

Therefore,

In 1965

z score = [ $2,300 - $2,650] ÷ 1,000

= -0.35

In 2011

z score = [ $28,000 - $30,500 ] ÷ 9,000

= -0.278

Since,

The standard score in 2011 is higher than in 1965

Hence,

Car were more expensive in 2011