Solve the system of equations. 2x+2y+7z=9, 2x+6y+5z=7, 5x+2y+4z=9. a.x=3 y=-2 z=3 b.x=1 y=0 z=1 c.x=2 y=-1 z=0 d. x=0 y=1 z=2

A speed walker covered 4 1/2 mi in 3/4 hour. How far will he walk with the same pace in: 3 hours

suter [353]

18 miles hope this help please mark me brainliest if i did!

3 0

2 years ago

Need an answer, please need an answer, please

Troyanec [42]

Answer:

Hopefully it will help you... Thanks

6 0

2 years ago

∫ 5cos(x) - 2sec²(x) dx

daser333 [38]

$\bf \displaystyle \int [5cos(x) - 2sec^2(x)]dx\implies 5\int cos(x)dx~-~2\int sec^2(x)dx
\\\\\\
5sin(x)-2tan(x)+C$

5 0

2 years ago

The amount of time all students in a very large undergraduate statistics course take to complete an examination is distributed c

Anestetic [448]

Answer:

a) The mean is $\mu = 60$

b) The standard deviation is $\sigma = 9$

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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.

The probability a student selected at random takes at least 55.50 minutes to complete the examination equals 0.6915.

This means that when X = 55.5, Z has a pvalue of 1 - 0.6915 = 0.3085. This means that when $X = 55.5, Z = -0.5$