Answer:
<u>The probability that a randomly selected boy in school can run the mile in less than 348 seconds is 1.1%.</u>
Step-by-step explanation:
1. Let's review the information provided to us to answer the question correctly:
μ of the time a group of boys run the mile in its secondary- school fitness test = 440 seconds
σ of the time a group of boys run the mile in its secondary- school fitness test = 40 seconds
2. Find the probability that a randomly selected boy in school can run the mile in less than 348 seconds.
Let's find out the z-score, this way:
z-score = (348 - 440)/40
z-score = -92/40 = -2.3
Now let's find out the probability of z-score = -2.3, using the table:
p (-2.3) = 0.0107
p (-2.3) = 0.0107 * 100
p (-2.3) = 1.1% (rounding to the next tenth)
<u>The probability that a randomly selected boy in school can run the mile in less than 348 seconds is 1.1%.</u>
Answer:
positive
Step-by-step explanation:
a negative times a negative is always a positive
since triangles are similar
4/x = 7x/7
=》 4/x = x
=》x^2 = 4
=》 x = 2
for right triangles a^2 = b^2+c^2
DF^2 = 7^2+2^2 = 53
=》 DF = 7.28
perimeter of DEF = 7 +2+7.28 = 16.28
