Brian is 8 and his brother is twice his age. How old will his brother be when brian is 11?.

2 answers:

5 0

If brian is 8 and his brother is twice his age, his brother is 16. His brother is 8 years older so when Brian is 11 he will be 19

ArbitrLikvidat [17]1 year ago

5 0

Twice means multiplying by 2 . So when Brian is 11 his brother will be 22

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April shoots an arrow upward at a speed of 80 ft/sec from a platform of 25 ft. High. The pathway of the arrow can be represented

soldi70 [24.7K]

Answer:

125feet

Step-by-step explanation:

Given the equation that modeled the height expressed as h = -16t^2 + 80t + 25, where h is the height and t is the time in seconds.

The arrow reaches the maximum height at dh/dt = 0

dh/dt = -32t + 80

0= -32t+80

32t = 80

t = 80/32

t = 2.5secs

substitute t = 2.5 into the formula;

h = -16t^2 + 80t + 25

h = -16(2.5)^2 + 80(2.5) + 25

h = -16(6.25)+225

h = -100+225

h = 125

Hence the maximum height the arrow reaches is 125feet

4 0

2 years ago

The wildlife department has been feeding a special food to rainbow trout fingerlings in a pond. based on a large number of obser

Liono4ka [1.6K]

The normal distribution curve for the problem is shown below

We need to standardise the value X=405.5 by using the formula

$z-score= \frac{X-Mean}{Standard Deviation}$
$z-score= \frac{405.5-402.7}{8.8} =0.32$

We now need to find the probability of z=0.32 by reading the z-table

Note that z-table would give the reading to the left of z-score, so if your aim is to work out the area to the right of a z-score, then you'd need to do:

$P(Z\ \textgreater \ z)=1 - P(Z\ \textless \ z)$

from the z-table, the reading $P(Z\ \textless \ 0.32)$ gives 0.6255

hence,
$P(Z\ \textgreater \ 0.32)=1-0.6255=0.3475$

The probability that the mean weight for a sample of 40 trout exceeds 405.5 gram is 0.3475 = 34.75%