Answer:
2.8
Step-by-step explanation:
To find the mean add all the values and divide by the amount of values and when you add everything up it is 14 and dividr by 5 to get 2.8
Answer: 
Step-by-step explanation:

Answer:
Z-scores between -0.86 and 0.86 separate the middle 61% of the distribution from the area in the tails of the standard normal distribution
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

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 p-value, we get the probability that the value of the measure is greater than X.
Middle 61%
Between the 50 - (61/2) = 19.5th percentile and the 50 + (61/2) = 80.5th percentile.
19.5th percentile.
Z with a pvalue of 0.195. So Z = -0.86
80.5th percentile.
Z with a pvalue of 0.805. So Z = 0.86.
Z-scores between -0.86 and 0.86 separate the middle 61% of the distribution from the area in the tails of the standard normal distribution
Solution:
we are given in the problem that
So far, 18 of the 25 students in your class have turned in field trip permission slips.
we have been asked to find
What percent of your classmates have turned in permission slips?
Required Percentage
Simplify we get
Required Percentage
Hence 72% percent of your classmates have turned in permission slips.
Answer:
x = 5
Step-by-step explanation:
The area (A) of a triangle is calculated as
A =
bh ( b is the base and h the height )
Here b = x + 3 and h = 2x - 5 , thus
(x + 3)(2x - 5) = 20 ( multiply both sides by 2 )
(x + 3)(2x - 5) = 40 ← expand factors on left using FOIL
2x² + x - 15 = 40 ( subtract 40 from both sides )
2x² + x - 55 = 0 ← in standard form
(x - 5)(2x + 11) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 5 = 0 ⇒ x = 5
2x + 11 = 0 ⇒ 2x = - 11 ⇒ x = - 5.5
But x > 0 , hence x = 5