Answer:
P(X < 80) = 0.89435.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
![\mu = 60, \sigma = 16](https://tex.z-dn.net/?f=%5Cmu%20%3D%2060%2C%20%5Csigma%20%3D%2016)
P(X < 80)
This is the pvalue of Z when X = 80. So
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![Z = \frac{80 - 60}{16}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7B80%20-%2060%7D%7B16%7D)
![Z = 1.25](https://tex.z-dn.net/?f=Z%20%3D%201.25)
has a pvalue of 0.89435.
So
P(X < 80) = 0.89435.
This is a proportion. First you take the numerator times the denominator that is already solved. In this case you will take 5 times 7 and get 35. You then take 35 divided by 4 and get your answer.
➻ In a group of 40 people, 27 can speak English and 25 can speak Spanish.
➻ The required number of people who can speak both English and Spanish .
<u>Consider</u> ,
➻ A → Set of people who speak English.
➻ B → Set of people who speak Spanish
➻ A∩B → Set of people who can speak both English and Spanish
➻ n(A∪B) = n(A) + n (B) - n(A∩B)
➻ 40 = 27 + 25 - n (A∩B)
➻ 40 = 52 - n (A∩B)
➻ n (A∩B) = 52 - 40
➻ ∴ n (A∩B) = 12
∴ Required Number of persons who can speak both English and Spanish are <u>12 .</u>
━━━━━━━━━━━━━━━━━━━━━━
![\qquad {\: \:\bigstar \: {\underline{\overline{\boxed{\bf{Verification}}}}}\: \bigstar}](https://tex.z-dn.net/?f=%20%20%20%5Cqquad%20%7B%5C%3A%20%5C%3A%5Cbigstar%20%5C%3A%20%20%7B%5Cunderline%7B%5Coverline%7B%5Cboxed%7B%5Cbf%7BVerification%7D%7D%7D%7D%7D%5C%3A%20%5Cbigstar%7D%20)
➻ n(A∪B) = n(A) + n (B) - n(A∩B)
➻ 40 = 27 + 25 - 12
➻ 40 = 52 - 12
➻ 40 = 40
➻ ∴ L.H.S = R.H.S
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Answer:
132 cm
Step-by-step explanation:
pie = 22/7
42 times 22/7 = 132cm
Answer:
8 lbs 5 oz
Step-by-step explanation:
When you add 3 lbs, 2 lbs, and 2 lbs you get 7 lbs.
There are 16 oz in a lb. When you add the number of oz you get 21 oz which is the same as 1 lb and 5 oz.
you then add 7 lbs to 1 lb and 5 oz and get 8 lbs and 5 oz.