a. What percent of people earn less than $40000?
Solution: Let S be the random variable of a salary of employee (in $), S ~ N(50000,20000). Then the random
variable X =−50000
20000
~N(0,1).
( < 40000) = ( <
40000 − 50000
20000 ) = ( < −0.5) = (−0.5) = 0.3085375.
Here Φ(x) denotes the cumulative distribution function of a standard normal distribution.
Answer: 31%.
b. What percent of people earn between $45000 and $65000?
Solution:
(45000 < < 65000) = (
45000 − 50000
20000 < <
65000 − 50000
20000 ) = (−0.25 < < 0.75)
= (0.75) − (−0.25) = 0.7733726 − 0.4012937 = 0.3720789.
Answer: 37%.
c. What percent of people earn more than $70000?
Solution:
( > 70000) = ( >
70000 − 50000
20000 ) = ( > 1) = 0.8413447.
Answer: 84%.
These statistics are impossible: all students who ride bike and use crossing guard ride a bike, so the proportion of students who ride a bike and use the crossing guard must be less than or equal to the proportion of students who ride a bike. This is not true in the given stats; 0.12 > 0.1
Answer:
20ft
Explanation:
You multiply the model length by the scale factor to find the actual length. <u>If the scale factor is less than zero, then the actual size will be smaller than the model</u>. Therefore, your answer would be 20ft.
Specifically, the scale factor is .8 if the actual size is 20ft, 1 if the actual size is 25ft, and 1.2 if the actual size is 30ft.
by pythagorean formula, the last side is √(61)
by cos rule
cos A
A = 39.81
Answer:
Step-by-step explanation:
Using the slope formula:
