The lifespan of lions in a particular zoo are normally distributed. The average lion lives 10 years: the standard deviation is 1.4 years. Use the empirical rule (68-95-99.7%) to estimate the probability of a lion living less than 7.2 years

2.5% probability of a lion living less than 7.2 years

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 10

Standard deviation = 1.4

Probability of a lion living less than 7.2 years

The normal distribution is symmetric, which means that 50% of the measures are above the mean and 50% are below.

7.2 = 10 - 2*1.4

So 7.2 is two standard deviations below the mean.

By the empirical rule, of those 50% of the measures below the mean, 95% is within 2 standard deviations of the mean, that is, between 7.2 and 10, and 5% are less than 7.2. So

p = 0.05*0.5 = 0.025

2.5% probability of a lion living less than 7.2 years

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.