Answer:
21.94% of people aged 20 to 34 have IQs between 125 and 150.
Step-by-step explanation:
<u>The complete question is:</u> Scores on the Wechsler Adult Intelligence Scale (a standard IQ test) for the 20 to 34 age group are approximately Normally distributed with μ = 110 and σ = 25.
What percent of people aged 20 to 34 have IQs between 125 and 150?
Let X = <u><em>Scores on the standard IQ test for the 20 to 34 age group</em></u>
SO, X ~ Normal(
)
The z-score probability distribution for the normal distribution is given by;
Z = 
~ N(0,1)
where, 
= population mean = 110
= standard deviation = 25
Now, the percent of people aged 20 to 34 have IQs between 125 and 150 is given by = P(125 < X < 150) = P(X < 150) - P(X 
125)
P(X < 150) = P( < 
) = P(Z < 1.60) = 0.9452
P(X 125) = P( 
) = P(Z 0.60) = 0.7258
The above probability is calculated by looking at the value of x = 1.60 and x = 0.60 which has an area of 0.9452 and 0.7258.
Therefore, P(125 < X < 150) = 0.9452 - 0.7258 = 0.2194 or 21.94%
Step-by-step explanation:
Note that t = d/r where t is time, d is distance, and r is rate/speed.
We can come up with two equations with the information given and the equation:
t_1 hr = (10 km)/(x km/hr)
t_2 hr = (12 km)/(x - 1 km/hr)
<em>where t_1 is the time taken to run the 10km the first day and t_2 is the time taken to run the 12km the second day.</em>
We know that 30 minutes is 1/2 of an hour and that t_1 is 30 minutes less than t_2 (as stated in the question). Therefore, we can write:
t_1 = t_2 - 1/2
Substituting the values we derived:
(10 km)/(x km/hr) = (12 km)/(x - 1 km/hr) -1/2
Then we can evaluate by multiplying by 2x(x-1) on both sides:
20(x-1) = 24x - (x)(x-1)
20x - 20 = 24x - x^2 + x
x^2 -5x -20 = 0
And we are done.
I hope this helps! :)
Answer:
A: 22
Step-by-step explanation:
2The interquartile range begins at 45 and ends at 67. All you need to do is subtract 45 drom 67, and you get 22.
