contestada

A standardized test has a mean of 110 points and a standard deviation of 10 points. John scored at the 98th percentile on the test. Find his score to the nearest whole number.

Respuesta :

Answer: his score 131 points

Step-by-step explanation:

Assuming the scores in the standardized test are normally distributed, we would apply the formula for normal distribution which is expressed as

z = (x - µ)/σ

Where

x = standardized test scores.

µ = mean score

σ = standard deviation

From the information given,

µ = 110 points

σ = 10 points

Looking at the normal distribution table, the z score that corresponds to the 98 percentile is 2.06

2.06 = (x - 110)/10

Cross multiplying, it becomes

2.06 × 10 = x - 110

2.06 = x - 110

x = 20.6 + 110

x = 130.6

Approximately, x = 131

Standard deviation is defined as the measure of how a dispersed value, data, or set of number is in relation to its mean.

Given:

Mean = 110

S. Deviation = 10

From the formula of standard deviation, we have:

[tex]z = \dfrac{x - u}{\sigma}[/tex]

where,

x = score, [tex]\sigma[/tex] = standard deviation, and u = mean or raw value

Now,

z-score corresponding to 98 percentile is 2.06.

Substituting the values in the above formula, we get:

[tex]\begin{aligned} 2.06 &=\dfrac{x -110}{10}\\\\2.06 \times 10 &= x -110\\\\20.6 &= x - 110\\\\20.6 + 110 &= x\\\\130.6 &= x \end[/tex]

Thus, the score to the nearest whole number is 131.

To know more about standard deviation, refer to the following link:

https://brainly.com/question/12402189