Answer:
Probability that a randomly selected woman's gestation period will be between 261 and 279 days is 0.68.
Step-by-step explanation:
We are given that the average human gestation period is 270 days with a standard deviation of 9 days. The period is normally distributed.
Firstly, Let X = women's gestation period
The z score probability distribution for is given by;
Z = 
~ N(0,1)
where, 
= average gestation period = 270 days
= standard deviation = 9 days
Probability that a randomly selected woman's gestation period will be between 261 and 279 days is given by = P(261 < X < 279) = P(X < 279) - P(X 
261)
P(X < 279) = P( < 
) = P(Z < 1) = 0.84134
P(X 261) = P( 
) = P(Z -1) = 1 - P(Z < 1)
= 1 - 0.84134 = 0.15866
<em>Therefore, P(261 < X < 279) = 0.84134 - 0.15866 = 0.68</em>
Hence, probability that a randomly selected woman's gestation period will be between 261 and 279 days is 0.68.
Birmingham and Montgomery both have a state sales tax rate of 4 percent and a local tax rate of 6 percent – although the report notes that part of Birmingham lies in Shelby County, meaning the combined rate is only 9 percent in some parts of the city.
Answer:
Third option
Step-by-step explanation:
We can't factor this so we need to use the quadratic formula which states that when ax² + bx + c = 0, x = (-b ± √(b² - 4ac)) / 2a. However, we notice that b (which is 6) is even, so we can use the special quadratic formula which states that when ax² + bx + c = 0 and b is even, x = (-b' ± √(b'² - ac)) / a where b' = b / 2. In this case, a = 1, b' = 3 and c = 7 so:
x = (-3 ± √(3² - 1 * 7)) / 1 = -3 ± √2
Answer:
She did not use the reciprocal of the divisor.
She added the numerators.
