4πr2
= 4×π×42
= 64π
= 201.06192982975 inches2
The answer should be the last one
Using the normal distribution, it is found that 1851 people would have an IQ less than 115.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
The mean and the standard deviation are given, respectively, by:

The proportion of IQ scores less than 115 is the <u>p-value of Z when X = 115</u>, hence:


Z = 1
Z = 1 has a p-value of 0.8413.
Out of 2200 people:
0.8413 x 2200 = 1851.
More can be learned about the normal distribution at brainly.com/question/27643290
#SPJ1
Answer:
x = 136/35; y = -⁹/₁₀
Step-by-step explanation:
(1) 7x + 8y = 20
(2) 7x – 2y = 29 Subtract (2) from (1)
10y = -9 Divide each side by 10
(3) y = -⁹/₁₀ Substitute (3) into (1)
7x - 2(-⁹/₁₀) = 29
7x + 18/10 = 29 Subtract 18/10 from each side
7x = 29 - 18/10
7x = (290 - 18)/10
7x = 272/10 Divide each side by 7
x = 272/70
x = 136/35
x = 136/35; y = -⁹/₁₀
Check:
(1) 7(136/35) + 8(-⁹/₁₀) = 20
136/5 - 72/10 = 20
136/5 - 36/5 = 20
100/5 = 20
20 = 20
(2) 7(136/35) – 2(-⁹/₁₀) = 29
136/5 + 18/10 = 29
136/5 + ⁹/₅ = 29
145/5 = 29
29 = 29
Answer: So the number of outcomes with exactly 4 tails is 720/2/24 = 15. Finally we can now calculate the probability of getting exactly 4 tails in 6 coin tosses as 15/64 = 0.234 to 3 decimal places.
Answer:
steps and answers in the pic..hope u can understand the calculations...