The graph below shows the relationship between hours of exercise and hours of screen time for a group of 5 friends on Thursday.

Suppose ACT Reading scores are normally distributed with a mean of 21.4 21.4 and a standard deviation of 5.9 5.9 . A university

Nutka1998 [239]

Answer:

29.2

Step-by-step explanation:

Mean = 21.4

Standard deviation = 5.9%

The minimum score required for the scholarship which is the scores of the top 9% is calculated using the Z - Score Formula.

The Z- score formula is given as:

z = x - μ /σ

Z score ( z) is determined by checking the z score percentile of the normal distribution

In the question we are told that it is the students who scores are in the top 9%

The top 9% is determined by finding the z score of the 91st percentile on the normal distribution

z score of the 91st percentile = 1.341

Using the formula

z = x - μ /σ

Where

z = z score of the 91st percentile = 1.341

μ = mean = 21.4

σ = Standard deviation = 5.9

1.341= x - 21.4 / 5.9

Cross multiply

1.341 × 5.9 = x - 21.4

7.7526 = x -21.4

x = 7.7526 + 21.4

x = 29.1526

The 91st percentile is at the score of 29.1526.

We were asked in the question to round up to the nearest tenth.

Approximately, = 29.2

Step-by-step explanation:

7 0

3 years ago

tina bought some nail polish and lip gloss at the store. the nail polish cost $4.50 per bottle and lip gloss cost $7 per tube. t

viktelen [127]

5 nail polish and 4 lip gloss

5 x 4.5 =22.5
4 x 7 =28
28+22.5=50.50

5 0

3 years ago

What is the sum of 5.439 + 3.200

Oliga [24]

Answer:

8.639

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7 0

3 years ago

The mean time it takes to walk to the bus stop is 8 minutes (with a standard deviation of 2 minutes) and the mean time it takes

kifflom [539]

We have been given for a normal distribution the mean time it takes to walk to the bus stop is 8 minutes with a standard deviation of 2 minutes. And the mean time it takes for the bus to get to school is 20 minutes with a standard deviation of 4 minutes.

(a) Average time that it would take reach school can be obtained by adding the average times.

8+20 = 28 minutes.

(b) Standard deviation of the trip to school can be found as:

$\sigma =\sqrt{2^{2}+4^{2}}=\sqrt{4+16}=\sqrt{20}=4.47$