Answer:
X=5,-2
Steps:
Get everything to the same side:
X^2-3x-10=0
Then factor:
(X-5)(x+2)=0
Answer:
a) 229 and 305 days
b) 229 days or less
c) 305 days or more
Step-by-step explanation:
The Empirical Rule(68-95-99.7 rule) states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 267
Standard deviation = 19
(a) Between what values do the lengths of the middle 95% of all pregnancies fall?_____________and___________days
By the Empirical rule, 95% of all pregnancies fall within 2 standard deviations of the mean.
So
267 - 2*19 = 229 days
to
267 + 2*19 = 305 days
(b) How short are the shortest 2.5% of all pregnancies?______days or less
95% of all pregnancies fall within 2 standard deviations of the mean. The other 5% are more than 2 standard deviations from the mean. Since the distribution is symmetric, 2.5% is more than 2 standard deviations below the mean(shortest 2.5%) and 2.5% is more than 2 standard deviations above the mean(longest 2.5%). So
267 - 2*19 = 229 days
c) How long do the longest 2.5% of pregnancies last?________days or more
Explanation in b)
267 + 2*19 = 305 days
Answer:
Step-by-step explanation:
Part A:
Mark did not round to the nearest hundreds, he rounded to the nearest tens.
Option A (Incorrect):
271 and 582 are normally not rounded down, unless we are using limits coming from the left and a unique equation.
Option B (Incorrect):
271 as the same problem as option A, but 582 rounding to 600 is correct. It doesn't make sense to round both numbers differently, unless stated.
Option C (Incorrect):
271 rounding to 300 is correct, but 582 is not normally rounded down to 500 unless we are using limits coming from the left and a unique equation. Unless stated, don't round both numbers differently.
Option D (Correct):
271 rounded to 300 and 582 rounded to 600 looks correct for rounding to the hundreds.
Part B:
There are two ways to solve this question:
One way:
271 + 582 = 853
Round 853 to the nearest hundred for 900
(Note: Round 853 to the nearest tens for 850.)
Second way:
271 + 582
Round Numbers:
300 + 600
= 900
The answer should be B.
5(6.86x)
Answer:
m would be 1
Step-by-step explanation:
5^3 is 125 so it would be 1. I am pretty sure. Sorry if Im wrong!
