Question

Statistics

2. A pilot study is run to investigate the feasibility of recruiting pregnant women into a study of risk factors for preterm delivery. Women are invited to participate at their first clinical visit for prenatal care. The following represent the gestational ages in weeks of women who consent to participate in the study.

10 16 25 24 6 12 15 19

a. Compute the sample mean gestational age.

b. Compute the sample standard deviation of gestational age.

c. Compute the median gestational age

d. What proportion of the sample enroll in first trimester of pregnancy (i.e., between 1-13 weeks, inclusive, of pregnancy)?

Verified

### Question 37038

Statistics

Let {X1, X2,...XN} be a random sample where each random variable X, has a PDF given by
f(x)=\frac{1}{(\lambda+\mu)} e^{\frac{1}{2}[-(\operatorname{sign}(x)+1)(x / \lambda)+(\operatorname{sign}(x)-1)(x / \mu)]}
\operatorname{sign}(x)=\left\{\begin{array}{rr} 1, & x \geq 0 \\ -1, & x<0 \end{array}\right.
where the sign function is defined as
and N denoting an integer, and the parameters , µ satisfying 1 > 0, µ > 0.In the followings provide complete derivations and explanations of results.
a) Find the likelihood function and the log-likelihood function for the parameters 1,µ
b) Find Maximum Likelihood (ML) estimators for the parameters 1, u.
c) Determine if these ML estimators are unbiased for N = 1.

### Question 33214

Statistics

How many ways can 4 pairs of socks be chosen from 16 pairs?
O 1820
O 496
O43680

### Question 33213

Statistics

How many subsets of {1,2,.... 20} have three elements?
O 5814
01140
O 969
O 6840

### Question 33212

Statistics

Suppose there are eight different colors of flowers in a flower vase. How many different ways we select three different colors of flowers from the vase?
0 6720
O 336
06
56O 56

### Question 33209

Statistics

How many eight-digit integers are there that do not contain repeated digits?
O 10-9 8 7-6 5-4-3
09.9.8-7-6 5 4-3
O P(10, 8)
O P(9, 8)

### Question 33207

Statistics

How many 2-permutations of {a, b, c, d)?
O 12
O 24
O 10
O 35

### Question 33206

Statistics

How many permutations of the letters ABCDEFG contain the string "BC" and "FG'as a substrings?
O 120
0720
O 2520

### Question 33205

Statistics

How many permutations of the letters ABCDEFG contain the string "ABC as a substring?
O 5040
0 120
O 24
0720

### Question 33204

Statistics

How many different order can there a set with {a, b. c. 4. 5. Š}?
O 120
O 1040
0720
O 24

### Question 33203

Statistics

How many numbers from the set of integers between 1 and 1000, inclusive, are divisible by 2 or 5.
O 600
O 500
O 300
0400