Answer:
d i believe its do but i need 20 characters
Answer:
b) 6.68%
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

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 p-value, we get the probability that the value of the measure is greater than X.
The mean score on the scale is 50. The distribution has a standard deviation of 10.
This means that 
Matthew scores a 65. What percentage of people could be expected to score the same as Matthew or higher on this scale?
The proportion is 1 subtracted by the p-value of Z when X = 65. So



has a p-value of 0.9332.
1 - 0.9332 = 0.0668
0.0668*100% = 6.68%
So the correct answer is given by option b.
Answer:
Option 4 is correct. The length of PR is 6.4 units.
Step-by-step explanation:
From the given figure it is noticed that the triangle PQR and triangle MQR.
Let the length of PR be x.
Pythagoras formula

Use pythagoras formula for triangle PQM.





The value of PM is 10. The length of PR is x, so the length of MR is (10-x).
Use pythagoras formula for triangle PQR.


.....(1)
Use pythagoras formula for triangle MQR.



.... (2)
From equation (1) and (2) we get




Therefore length of PR is 6.4 units and option 4 is correct.
<h2>
The required positive number is 7.</h2>
Step-by-step explanation:
Let the number = x
To find, the positive number = ?
According to question,

⇒
- 3x - 28 = 0
By Factorisation method,
⇒
- 7x + 4x - 28 = 0
⇒ x(x - 7) + 4(x - 7) = 0
⇒ (x - 7)(x + 4) = 0
⇒ x - 7 = 0 or, x + 4 = 0
⇒ x = 7 or, x = - 4 [ - 4 is a negative number)
⇒ x = 7
Thus, the required positive number is 7.
D because it has to be a chord due to being perpendicular to a diameter