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How can I use the normal distribution table to find probabilities other than P(z<Z)?

The normal distribution tables show, for a given Z value, the probability that the random variable z takes a value less than Z or P(z&lt;Z). This is also the area under the normal distribution curve up to Z....
HA
Answered by Holi A. • Maths tutor
4646 Views

In an office there are twice as many females as males. 1/4 of the females wear glasses. 3/8 of the males wear glasses. 84 people in the office wear glasses. Work out the number of people in the office.

office that is females with glasses=(2/3) (1/4)=1/6 office that is males wearing glasses=(1/3) (3/8)=1/8 (1/6)/(1/8) = 8/6=4/3 so there is a ratio of 4:3 women to men wearing glasses 84*(4/7)=12 4=48 women w...
WJ
Answered by William J. • Maths tutor
17157 Views

Olly drove 56 km from A to B. He then drives 61 km from B to C. Olly’s average speed from A to B was 70 km/h. Olly took 75 minutes to drive from B to C. Work out Olly’s average speed for his total drive from A to C.

Key fact: Average speed = total distance/ total timeStep 1: find the time taken for Olly to travel from A to B. Using the formula: time taken = distance travelled / speed(56/70 = 0.8 hrs = 48 mins)Step 2: fi...
SW
Answered by Sacha W. • Maths tutor
12761 Views

F = 5i + 3j. Find the magnitude and direction of F?

i is the unit vector (magnitude of 1) in the direction of the positive x-axis. j is the unit vector in the direction of the positive y-axis. The magnitude of F would be the length of the hypotenuse of a righ...
RI
Answered by Rafiqul I. • Maths tutor
21558 Views

Given the area of the pool is 63m^2, what is the value of x?

(There is a diagram showing a rectangle with one side labelled x+4 and another labelled x+6)Area = (x+4)(x+6)63m^2 = x 2 +10x+240 = x 2 +10x-390 = (x-3)(x+13) x-3=0 so x=3x+13=0 gives x=-13, which cannot be ...
TG
Answered by Toby G. • Maths tutor
3581 Views