Correlation coefficient (r) = [nΣxy - (Σx)(Σy)] / [sqrt(nΣx^2 - (Σx)^2)sqrt(nΣy^2 - (Σy)^2)]
Σx = 21 => (Σx)^2 = 21^2 = 441
Σy = 671 => (Σy)^2 = 671^2 = 450,241
Σx^2 = 1 + 4 + 9 + 16 + 25 + 36 = 91
Σy^2 = 98^2 + 101^2 + 109^2 + 117^2 + 119^2 + 127^2 = 75,665
Σxy = 1(98) + 2(101) + 3(109) + 4(117) + 5(119) + 6(127) = 2,452
r = [6(2,452) - 21(671)] / [sqrt(6(91) - 441)sqrt(6(75,665) - 450,241)] = 621/sqrt(105)sqrt(3749) = 0.99
option b is the correct answer.
Answer: C
both a and b
Step-by-step explanation:
Both options A and B deals with the number of trials required for a single success. Thus, they are negative binomial distribution where the number of successes (r) is equal to 1.
The geometric distribution is a special case of the negative binomial distribution that deals with the number of trials required for a single success.
Answer:
The standard error of the proportion is 0.0367.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the standard error is 
In this question:

So

The standard error of the proportion is 0.0367.
She made a mistake when she subtracted x1 from x2.
Step-by-step explanation:
Step 1 :
a)
The formula used by Lorena to calculate the slope between 2 points is correct
So the statement given in option 1 is not the reason for her mistake
Step 2:
b)
She has taken the fourth and fifth point and correctly used the x and y co ordinates to calculate the slope
Hence the statement in second option is not true
Step 3:
c)
While calculating the slope the denominator is -2 - (-4) . This gives 2 as the answer. But she has made a mistake in this subtraction giving -6 as the answer.
Hence she has made a mistake in subtracting x1 from x2 and this statement is true
Step 4:
d)
She has not made any mistake in subtracting y1 from y2. Hence this statement is not true