Managers at Matthew's Sporting Goods are concerned that the dumbbells from one of the store's new suppliers are poorly made. To investigate, the managers used a precision scale to weigh a random sample of 50 weights labeled "30 kg." They found that the dumbbells in the sample weighed an average of 30.1 kilograms, with a standard deviation of 3 kilograms. Find a 90% confidence interval for the mean weight of "30 kg" dumbbells manufactured by the new supplier.
Round your answers to the nearest tenth.

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x

134.6 us dollars

step-by-step explanation:

1 us dollar = 1.33 canadian dollars

so, 150 us dollars = 150 × 1.33 = $199.5.

in canada, the money mitchell spent = 20 canadian dollars.

remaining canadian dollars with him = 199.5 - 20 = 179.5.

after mitchell returned to us, he exchanged the remaining canadian dollars to us dollars.

179.5 canadian dollars = 179.5 × 0.75 = 134.6 us dollars.