Answer:
D) 15
Step-by-step explanation:
This is an arithmatic progression.
The formula for the sum of arithmatic progression is
[tex]s = \frac{n}{2} (2a + (n - 1)d)[/tex]
where d is the common difference between successive terms and a is the first term. By applying this formula,
[tex]120 = \frac{n}{2} (2(1) + (n - 1)(1)) \\ 120 = \frac{n}{2} (1 + n) \\ n(1 + n) = 240 \\ n {}^{2} + n - 240 = 0 \\ (n - 15)(n + 16) = 0 \\ n = 15 \: or \: n = - 16(reject)[/tex]
please help! I cant figure this out!
What is the product?
In an extensive study involving thousands of British children, Arden and Plomin (2006) found significantly higher variance in the intelligence scores for males than for females. Following are hypothetical data, similar to the results obtained in the study. Note that the scores are not regular IQ scores but have been standardized so that the entire sample has a mean of M 5 10 and a standard deviation of s 5 2. a. Calculate the mean and the standard deviation for the sample of n 5 8 females and for the sample of n 5 8 males. b. Based on the means and the standard deviations, describe the differences in intelligence scores for males and females.
Answer:
mean value of female = 10.000
standard deviation of female = 1.604
mean value of male = 10.000
standard deviation of male = 2.449
Step-by-step explanation:
Given:
n=8 females
n=8 males
The objective is to find the mean and deviation and also based on the mean and the standard deviation have to describe the differences in intelligence scores for males and females
Solution:
The mean and the standard deviation are found by using MINITAB
The MINITAB procedure is explained as follows,
Step 1
choosing start > Basic statistics > Display Descriptive Statistics
Step 2
In variables supposed to enter the columns Female and Male
Step 3
Here choosing option statistics and select Mean and standard deviation
Step 4
Finally clicking OK
MINITAB output is as follows,
variable Mean standard deviation
Female 10.000 1.604
Male 10.000 2.449
b)
From the MINITAB output the mean are same for females and males.
Here the standard deviation of females is less than the standard deviation of males. That is the male scores are more variable when compared to female scores.