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3 years ago

Really struggling plz help with all of them thanks

Mathematics

1 answer:

ollegr [7]3 years ago

3 0

First, look at the whole number if it is 12, it will go near the 1 on the number line, next look at the fraction,
if its 1/2 change it to be 2/4. Next count the lines in between the number. There are 4 lines. If it is 3/4, count 3 lines and put the fraction there. So 41/4 would be the 4 and 1 line next to it.

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Median of 12,13,19,16,32,15,13

Katena32 [7]

We will first put this data in ascending order
12,13,13,15,16,19,32
We then center in on the middle number, we first can “mark out” the highest and lowest number and repeat until we have one number left

12,13,13,15,16,19,32

13,13,15,16,19

13,15,16

The median is 15

3 0

2 years ago

Read 2 more answers

Suppose a student's score on a standardize test to be a continuous random variable whose distribution follows the Normal curve.

blsea [12.9K]

Answer:

a) Percentage of students scored below 300 is 1.79%.

b) Score puts someone in the 90th percentile is 638.

Step-by-step explanation:

Given : Suppose a student's score on a standardize test to be a continuous random variable whose distribution follows the Normal curve.

(a) If the average test score is 510 with a standard deviation of 100 points.

To find : What percentage of students scored below 300 ?

Solution :

Mean $\mu=510$ ,

Standard deviation $\sigma=100$

Sample mean $x=300$

Percentage of students scored below 300 is given by,

$P(Z\leq \frac{x-\mu}{\sigma})\times 100$

$=P(Z\leq \frac{300-510}{100})\times 100$

$=P(Z\leq \frac{-210}{100})\times 100$

$=P(Z\leq-2.1)\times 100$

$=0.0179\times 100$

$=1.79\%$

Percentage of students scored below 300 is 1.79%.

(b) What score puts someone in the 90th percentile?

90th percentile is such that,

$P(x\leq t)=0.90$

Now, $P(\frac{x-\mu}{\sigma} < \frac{t-\mu}{\sigma})=0.90$

$P(Z< \frac{t-\mu}{\sigma})=0.90$

$\frac{t-\mu}{\sigma}=1.28$

$\frac{t-510}{100}=1.28$

$t-510=128$

$t=128+510$

$t=638$

Score puts someone in the 90th percentile is 638.

5 0

3 years ago

Caden took her basketball team out for dinner after their tournament the total cost for dinner was $120 she had a coupon for 30%

Dafna11 [192]

so 120 - 39 is 80 then minus the basketball and you get fortyfor

6 0

3 years ago

A large manufacturing plant uses lightbulbs with lifetimes that are normally distributed with a mean of 1200 hours and a standar

a_sh-v [17]

Answer:

The bulbs should be replaced each 1060.5 days.

Step-by-step explanation:

Problems of normally distributed samples are 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.

In this problem, we have that:

$\mu = 1200, \sigma = 60$

How often should the bulbs be replaced so that no more than 1% burn out between replacement periods?

This is the first percentile, that is, the value of X when Z has a pvalue of 0.01. So X when Z = -2.325.

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

$-2.325 = \frac{X - 1200}{60}$

$X - 1200 = -2.325*60$

$X = 1060.5$

The bulbs should be replaced each 1060.5 days.

4 0

2 years ago

Alan and Margot drive from City A to City B a distance of 147 miles. They take the same route and drive at constant speeds. Alan

S_A_V [24]

If one of them got there faster, who will it be?? 147 Miles keep that in mind ok. If they go on the Same route and Drive at Constant Speed. And Alan will start at 1:45 to 4:15. You will see the Difference of, 1:45 = 4:15 The 1 Has switched into the tens and the 4 Has Switched into The 100's. Alan Got there Fast. Margot Got there Faster. If you can Solve The Equation y=64x It will be 36y. 36 Miles speed. Well they need gas? we will find out later. Margot Got to City a To City B. so the Answer is. Margot Got there Fast Before Alan.

5 0

3 years ago