PLEADE HELP QUICK WILL MARK BRAINLIEST!!! ITS SIMPLFT IF UR GOOD AT THAT PLESEE HELP

Marcus borrowed 9000 from his bank to buy a car. The bank charged him a simple interest rate of 1.25%. By the time he paid back

snow_lady [41]

Answer:

2.5 years

Step-by-step explanation:

Given data

P=9000

r= 1.25%

A= 9281.25

The simple interest expression is given as

A=P(1+rt)

substitute

9281.25= 9000(1+0.0125*t)

9281.25=9000+112.5t

collect like terms

9281.25-9000=112.5t

281.25= 112.5t

t= 281.25/112.5

t= 2.5

Hence the time is 2.5 years

7 0

2 years ago

The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a

AlekseyPX

Answer:

The time that the boys need to beat in order to earn a certificate of recognition from the fitness association is 511.264 seconds.

Step-by-step explanation:

We are given that the time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a standard deviation of 40 seconds.

The fitness association wants to recognize the fastest 10% of the boys with certificates of recognition.

Let X = time for this event for boys in secondary school

SO, X ~ Normal( $\mu=460,\sigma^{2} =40^{2}$ )

The z-score probability distribution for normal distribution is given by;

Z = $\frac{X-\mu}{\sigma}$ ~ N(0,1)

where, $\mu$ = mean time = 460 seconds

$\sigma$ = standard deviation = 40 seconds

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) 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.

Now, it is given that the fitness association wants to recognize the fastest 10% of the boys with certificates of recognition, which means;

P(X > x) = 0.10 {where x is the required time which boy need to beat}

P( $\frac{X-\mu}{\sigma}$ > $\frac{x-460}{40}$ ) = 0.10