FIVIZZ: ROAD TO FINAL - MATHEMATICS 3

During a Mathematics Test, the marks obtained by 6000 students are normally distributed with mean of 55 and a standard deviation of 10. If 70% of the students passed the test, find the passing mark of the test.

• 45.39

• 49.76

• 59.92

• 60.24

The lengths of replacement car wiper blades are normally distributed with mean 28 cm and standard deviation 0.3 cm. Find the probability that the wiper blades are between 27.89 cm and 28.33 cm in length?

• 0.0574

• 0.5074

• 0.5047

• 0.7540

The lengths of replacement car wiper blades are normally distributed with mean 25 cm and standard deviation 0.2 cm. For a batch of 200 wiper blades, how many would be expected to be 25.3 cm or more in length?

Find x, y and z.

• x = 2, y = 3 and z = 6

• x = 2, y = 2 and z = 3

• x = 2, y = 1 and z = 3

• x = 2, y = 1 and z = 6

Forty percent of customers at a shop pay by credit card. For a random sample of 150 customers, find the probability that more than 60 customers will pay by credit card.

• 0.4681

• 0.9167

• 0.5319

• 0.0833

A fair coin is tossed 18 times. Find the probability of obtaining 14 or more heads.

• 0.0139

• 0.0248

• 0.0169

• 0.0325

Matrix F is a symmetrical matrix. Find x, y and z.

• x = -1, y = 0 and z = -1, -3

• x = -2, y = 1, -3 and z = -1, 0

• x = -2, y = -1, -3 and z = 0, -2

• x = -3, y = 1, -3 and z = 0, -2

The lengths of flower stems are normally distributed with mean 18.7 cm and standard deviation 2.4 cm. Stem lengths less than 14.5 cm are unacceptable at a florist's shop. In a batch of 275 flowers, estimate how many would be unacceptable.

• 9

• 11

• 10

• 12

• 10

• 12

• 7

• 8

In a colony, there are 55 members. Every member posts a greeting card to all the members. How many greeting cards were posted by them?

• 990

• 890

• 2970

• 1980