The duration of human pregnancies is not fixed. it is known that it varies according to a distribution which is roughly normal, with a mean of 266 days, and a standard deviation of 16 days. (source: figures are from moore and mccabe, introduction to the practice of statistics). according to the empirical rule (sd rule), the shortest 2.5% of pregnancies last less than how many days?

By the empirical rule, 95% of the distribution is within 2 standard deviations. Since the other 5% is split equally between the two tails of the distribution, the empirical rule says 2.5% will be below -2 standard deviations from the mean.

... 266 days - 2×(16 days) = 234 days

The shortest 2.5% of pregnancies last less than 234 days.

1/3

step-by-step explanation:

to find this, you can divide 12 by 4 which is 3 or you can multiply 4 until you reach 12 (4x3=12). both should give you 3, meaning theres three times less bananas than there are oranges.

answer:

step-by-step explanation:

here, the total dishes = 10

dishes having meat = 3 ( chicken, meatloaf and hamburger )

thus, the probability of having meat on the chosen dishes = number of dishes having meat / total dishes

=

therefore, the probability of not having meat = 1- the probability of having meat on the chosen dishes

=

=

=

⇒ option b is correct.