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
Factor the polynomial:
4u² – 20u + 25
Rewrite – 20u as – 10u – 10u, and then factor it by grouping:
= 4u² – 10u – 10u + 25
= 2u * (2u – 5) – 5 * (2u – 5)
= (2u – 5) * (2u – 5)
= (2u – 5)² <––– this is the answer.
I hope this helps. =)
Answer:
The points are randomly scattered with no clear pattern
The number of points is equal to those in the scatterplot.
Step-by-step explanation:
The points in the residual plot of the line of best fit that is a good model for a scatterplot are randomly scattered with no clear pattern (like a line or a curve).
The number of points in the residual plot is always equal to those in the scatterplot.
It doesn't matter if there are about the same number of points above the x-axis as below it, in the residual plot.
The y-coordinates of the points are not the same as the points in the scatterplot.
Answer: -9
Step-by-step explanation:
(6+3)÷(4-5)
Since 6+3 is 9 and 4-5 = -1
You do 9 divided by -1. It equals -9.
It is -9 since a positive divided by a negative number.
First round up 249.99 to 250.00
Then change the 4% into a decimal= 1.04
Now multiply so the equation is= 250 x 1.04 =
$260 as your answer!
